[portage.git] / pym / _emerge / __init__.py

#!/usr/bin/python -O
# Copyright 1999-2006 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: emerge 5976 2007-02-17 09:14:53Z genone $

import sys
# This block ensures that ^C interrupts are handled quietly.
try:
        import signal

        def exithandler(signum,frame):
                signal.signal(signal.SIGINT, signal.SIG_IGN)
                signal.signal(signal.SIGTERM, signal.SIG_IGN)
                sys.exit(1)
        
        signal.signal(signal.SIGINT, exithandler)
        signal.signal(signal.SIGTERM, exithandler)
        signal.signal(signal.SIGPIPE, signal.SIG_DFL)

except KeyboardInterrupt:
        sys.exit(1)

import array
from collections import deque
import fcntl
import formatter
import logging
import select
import shlex
import shutil
import textwrap
import urlparse
import weakref
import gc
import os, stat
import platform

try:
        import portage
except ImportError:
        from os import path as osp
        sys.path.insert(0, osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym"))
        import portage

from portage import digraph
from portage.const import NEWS_LIB_PATH

import _emerge.help
import portage.xpak, commands, errno, re, socket, time, types
from portage.output import blue, bold, colorize, darkblue, darkgreen, darkred, green, \
        nc_len, red, teal, turquoise, xtermTitle, \
        xtermTitleReset, yellow
from portage.output import create_color_func
good = create_color_func("GOOD")
bad = create_color_func("BAD")
# white looks bad on terminals with white background
from portage.output import bold as white

import portage.elog
import portage.dep
portage.dep._dep_check_strict = True
import portage.util
import portage.locks
import portage.exception
from portage.data import secpass
from portage.elog.messages import eerror
from portage.util import normalize_path as normpath
from portage.util import writemsg, writemsg_level
from portage.sets import load_default_config, SETPREFIX
from portage.sets.base import InternalPackageSet

from itertools import chain, izip
from UserDict import DictMixin

try:
        import cPickle as pickle
except ImportError:
        import pickle

try:
        import cStringIO as StringIO
except ImportError:
        import StringIO

class stdout_spinner(object):
        scroll_msgs = [
                "Gentoo Rocks ("+platform.system()+")",
                "Thank you for using Gentoo. :)",
                "Are you actually trying to read this?",
                "How many times have you stared at this?",
                "We are generating the cache right now",
                "You are paying too much attention.",
                "A theory is better than its explanation.",
                "Phasers locked on target, Captain.",
                "Thrashing is just virtual crashing.",
                "To be is to program.",
                "Real Users hate Real Programmers.",
                "When all else fails, read the instructions.",
                "Functionality breeds Contempt.",
                "The future lies ahead.",
                "3.1415926535897932384626433832795028841971694",
                "Sometimes insanity is the only alternative.",
                "Inaccuracy saves a world of explanation.",
        ]

        twirl_sequence = "/-\\|/-\\|/-\\|/-\\|\\-/|\\-/|\\-/|\\-/|"

        def __init__(self):
                self.spinpos = 0
                self.update = self.update_twirl
                self.scroll_sequence = self.scroll_msgs[
                        int(time.time() * 100) % len(self.scroll_msgs)]
                self.last_update = 0
                self.min_display_latency = 0.05

        def _return_early(self):
                """
                Flushing ouput to the tty too frequently wastes cpu time. Therefore,
                each update* method should return without doing any output when this
                method returns True.
                """
                cur_time = time.time()
                if cur_time - self.last_update < self.min_display_latency:
                        return True
                self.last_update = cur_time
                return False

        def update_basic(self):
                self.spinpos = (self.spinpos + 1) % 500
                if self._return_early():
                        return
                if (self.spinpos % 100) == 0:
                        if self.spinpos == 0:
                                sys.stdout.write(". ")
                        else:
                                sys.stdout.write(".")
                sys.stdout.flush()

        def update_scroll(self):
                if self._return_early():
                        return
                if(self.spinpos >= len(self.scroll_sequence)):
                        sys.stdout.write(darkgreen(" \b\b\b" + self.scroll_sequence[
                                len(self.scroll_sequence) - 1 - (self.spinpos % len(self.scroll_sequence))]))
                else:
                        sys.stdout.write(green("\b " + self.scroll_sequence[self.spinpos]))
                sys.stdout.flush()
                self.spinpos = (self.spinpos + 1) % (2 * len(self.scroll_sequence))

        def update_twirl(self):
                self.spinpos = (self.spinpos + 1) % len(self.twirl_sequence)
                if self._return_early():
                        return
                sys.stdout.write("\b\b " + self.twirl_sequence[self.spinpos])
                sys.stdout.flush()

        def update_quiet(self):
                return

def userquery(prompt, responses=None, colours=None):
        """Displays a prompt and a set of responses, then waits for a response
        which is checked against the responses and the first to match is
        returned.  An empty response will match the first value in responses.  The
        input buffer is *not* cleared prior to the prompt!

        prompt: a String.
        responses: a List of Strings.
        colours: a List of Functions taking and returning a String, used to
        process the responses for display. Typically these will be functions
        like red() but could be e.g. lambda x: "DisplayString".
        If responses is omitted, defaults to ["Yes", "No"], [green, red].
        If only colours is omitted, defaults to [bold, ...].

        Returns a member of the List responses. (If called without optional
        arguments, returns "Yes" or "No".)
        KeyboardInterrupt is converted to SystemExit to avoid tracebacks being
        printed."""
        if responses is None:
                responses = ["Yes", "No"]
                colours = [
                        create_color_func("PROMPT_CHOICE_DEFAULT"),
                        create_color_func("PROMPT_CHOICE_OTHER")
                ]
        elif colours is None:
                colours=[bold]
        colours=(colours*len(responses))[:len(responses)]
        print bold(prompt),
        try:
                while True:
                        response=raw_input("["+"/".join([colours[i](responses[i]) for i in range(len(responses))])+"] ")
                        for key in responses:
                                # An empty response will match the first value in responses.
                                if response.upper()==key[:len(response)].upper():
                                        return key
                        print "Sorry, response '%s' not understood." % response,
        except (EOFError, KeyboardInterrupt):
                print "Interrupted."
                sys.exit(1)

actions = frozenset([
"clean", "config", "depclean",
"info", "list-sets", "metadata",
"prune", "regen",  "search",
"sync",  "unmerge",
])
options=[
"--ask",          "--alphabetical",
"--buildpkg",     "--buildpkgonly",
"--changelog",    "--columns",
"--complete-graph",
"--debug",        "--deep",
"--digest",
"--emptytree",
"--fetchonly",    "--fetch-all-uri",
"--getbinpkg",    "--getbinpkgonly",
"--help",         "--ignore-default-opts",
"--keep-going",
"--noconfmem",
"--newuse",       "--nocolor",
"--nodeps",       "--noreplace",
"--nospinner",    "--oneshot",
"--onlydeps",     "--pretend",
"--quiet",        "--resume",
"--searchdesc",   "--selective",
"--skipfirst",
"--tree",
"--update",
"--usepkg",       "--usepkgonly",
"--verbose",      "--version"
]

shortmapping={
"1":"--oneshot",
"a":"--ask",
"b":"--buildpkg",  "B":"--buildpkgonly",
"c":"--clean",     "C":"--unmerge",
"d":"--debug",     "D":"--deep",
"e":"--emptytree",
"f":"--fetchonly", "F":"--fetch-all-uri",
"g":"--getbinpkg", "G":"--getbinpkgonly",
"h":"--help",
"k":"--usepkg",    "K":"--usepkgonly",
"l":"--changelog",
"n":"--noreplace", "N":"--newuse",
"o":"--onlydeps",  "O":"--nodeps",
"p":"--pretend",   "P":"--prune",
"q":"--quiet",
"s":"--search",    "S":"--searchdesc",
"t":"--tree",
"u":"--update",
"v":"--verbose",   "V":"--version"
}

def emergelog(xterm_titles, mystr, short_msg=None):
        if xterm_titles and short_msg:
                if "HOSTNAME" in os.environ:
                        short_msg = os.environ["HOSTNAME"]+": "+short_msg
                xtermTitle(short_msg)
        try:
                file_path = "/var/log/emerge.log"
                mylogfile = open(file_path, "a")
                portage.util.apply_secpass_permissions(file_path,
                        uid=portage.portage_uid, gid=portage.portage_gid,
                        mode=0660)
                mylock = None
                try:
                        mylock = portage.locks.lockfile(mylogfile)
                        # seek because we may have gotten held up by the lock.
                        # if so, we may not be positioned at the end of the file.
                        mylogfile.seek(0, 2)
                        mylogfile.write(str(time.time())[:10]+": "+mystr+"\n")
                        mylogfile.flush()
                finally:
                        if mylock:
                                portage.locks.unlockfile(mylock)
                        mylogfile.close()
        except (IOError,OSError,portage.exception.PortageException), e:
                if secpass >= 1:
                        print >> sys.stderr, "emergelog():",e

def countdown(secs=5, doing="Starting"):
        if secs:
                print ">>> Waiting",secs,"seconds before starting..."
                print ">>> (Control-C to abort)...\n"+doing+" in: ",
                ticks=range(secs)
                ticks.reverse()
                for sec in ticks:
                        sys.stdout.write(colorize("UNMERGE_WARN", str(sec+1)+" "))
                        sys.stdout.flush()
                        time.sleep(1)
                print

# formats a size given in bytes nicely
def format_size(mysize):
        if type(mysize) not in [types.IntType,types.LongType]:
                return str(mysize)
        if 0 != mysize % 1024:
                # Always round up to the next kB so that it doesn't show 0 kB when
                # some small file still needs to be fetched.
                mysize += 1024 - mysize % 1024
        mystr=str(mysize/1024)
        mycount=len(mystr)
        while (mycount > 3):
                mycount-=3
                mystr=mystr[:mycount]+","+mystr[mycount:]
        return mystr+" kB"


def getgccversion(chost):
        """
        rtype: C{str}
        return:  the current in-use gcc version
        """

        gcc_ver_command = 'gcc -dumpversion'
        gcc_ver_prefix = 'gcc-'

        gcc_not_found_error = red(
        "!!! No gcc found. You probably need to 'source /etc/profile'\n" +
        "!!! to update the environment of this terminal and possibly\n" +
        "!!! other terminals also.\n"
        )

        mystatus, myoutput = commands.getstatusoutput("gcc-config -c")
        if mystatus == os.EX_OK and myoutput.startswith(chost + "-"):
                return myoutput.replace(chost + "-", gcc_ver_prefix, 1)

        mystatus, myoutput = commands.getstatusoutput(
                chost + "-" + gcc_ver_command)
        if mystatus == os.EX_OK:
                return gcc_ver_prefix + myoutput

        mystatus, myoutput = commands.getstatusoutput(gcc_ver_command)
        if mystatus == os.EX_OK:
                return gcc_ver_prefix + myoutput

        portage.writemsg(gcc_not_found_error, noiselevel=-1)
        return "[unavailable]"

def getportageversion(portdir, target_root, profile, chost, vardb):
        profilever = "unavailable"
        if profile:
                realpath = os.path.realpath(profile)
                basepath   = os.path.realpath(os.path.join(portdir, "profiles"))
                if realpath.startswith(basepath):
                        profilever = realpath[1 + len(basepath):]
                else:
                        try:
                                profilever = "!" + os.readlink(profile)
                        except (OSError):
                                pass
                del realpath, basepath

        libcver=[]
        libclist  = vardb.match("virtual/libc")
        libclist += vardb.match("virtual/glibc")
        libclist  = portage.util.unique_array(libclist)
        for x in libclist:
                xs=portage.catpkgsplit(x)
                if libcver:
                        libcver+=","+"-".join(xs[1:])
                else:
                        libcver="-".join(xs[1:])
        if libcver==[]:
                libcver="unavailable"

        gccver = getgccversion(chost)
        unameout=platform.release()+" "+platform.machine()

        return "Portage " + portage.VERSION +" ("+profilever+", "+gccver+", "+libcver+", "+unameout+")"

def create_depgraph_params(myopts, myaction):
        #configure emerge engine parameters
        #
        # self:      include _this_ package regardless of if it is merged.
        # selective: exclude the package if it is merged
        # recurse:   go into the dependencies
        # deep:      go into the dependencies of already merged packages
        # empty:     pretend nothing is merged
        # complete:  completely account for all known dependencies
        # remove:    build graph for use in removing packages
        myparams = set(["recurse"])

        if myaction == "remove":
                myparams.add("remove")
                myparams.add("complete")
                return myparams

        if "--update" in myopts or \
                "--newuse" in myopts or \
                "--reinstall" in myopts or \
                "--noreplace" in myopts:
                myparams.add("selective")
        if "--emptytree" in myopts:
                myparams.add("empty")
                myparams.discard("selective")
        if "--nodeps" in myopts:
                myparams.discard("recurse")
        if "--deep" in myopts:
                myparams.add("deep")
        if "--complete-graph" in myopts:
                myparams.add("complete")
        return myparams

# search functionality
class search(object):

        #
        # class constants
        #
        VERSION_SHORT=1
        VERSION_RELEASE=2

        #
        # public interface
        #
        def __init__(self, root_config, spinner, searchdesc,
                verbose, usepkg, usepkgonly):
                """Searches the available and installed packages for the supplied search key.
                The list of available and installed packages is created at object instantiation.
                This makes successive searches faster."""
                self.settings = root_config.settings
                self.vartree = root_config.trees["vartree"]
                self.spinner = spinner
                self.verbose = verbose
                self.searchdesc = searchdesc
                self.root_config = root_config
                self.setconfig = root_config.setconfig
                self.matches = {"pkg" : []}
                self.mlen = 0

                def fake_portdb():
                        pass
                self.portdb = fake_portdb
                for attrib in ("aux_get", "cp_all",
                        "xmatch", "findname", "getFetchMap"):
                        setattr(fake_portdb, attrib, getattr(self, "_"+attrib))

                self._dbs = []

                portdb = root_config.trees["porttree"].dbapi
                bindb = root_config.trees["bintree"].dbapi
                vardb = root_config.trees["vartree"].dbapi

                if not usepkgonly and portdb._have_root_eclass_dir:
                        self._dbs.append(portdb)

                if (usepkg or usepkgonly) and bindb.cp_all():
                        self._dbs.append(bindb)

                self._dbs.append(vardb)
                self._portdb = portdb

        def _cp_all(self):
                cp_all = set()
                for db in self._dbs:
                        cp_all.update(db.cp_all())
                return list(sorted(cp_all))

        def _aux_get(self, *args, **kwargs):
                for db in self._dbs:
                        try:
                                return db.aux_get(*args, **kwargs)
                        except KeyError:
                                pass
                raise

        def _findname(self, *args, **kwargs):
                for db in self._dbs:
                        if db is not self._portdb:
                                # We don't want findname to return anything
                                # unless it's an ebuild in a portage tree.
                                # Otherwise, it's already built and we don't
                                # care about it.
                                continue
                        func = getattr(db, "findname", None)
                        if func:
                                value = func(*args, **kwargs)
                                if value:
                                        return value
                return None

        def _getFetchMap(self, *args, **kwargs):
                for db in self._dbs:
                        func = getattr(db, "getFetchMap", None)
                        if func:
                                value = func(*args, **kwargs)
                                if value:
                                        return value
                return {}

        def _visible(self, db, cpv, metadata):
                installed = db is self.vartree.dbapi
                built = installed or db is not self._portdb
                pkg_type = "ebuild"
                if installed:
                        pkg_type = "installed"
                elif built:
                        pkg_type = "binary"
                return visible(self.settings,
                        Package(type_name=pkg_type, root_config=self.root_config,
                        cpv=cpv, built=built, installed=installed, metadata=metadata))

        def _xmatch(self, level, atom):
                """
                This method does not expand old-style virtuals because it
                is restricted to returning matches for a single ${CATEGORY}/${PN}
                and old-style virual matches unreliable for that when querying
                multiple package databases. If necessary, old-style virtuals
                can be performed on atoms prior to calling this method.
                """
                cp = portage.dep_getkey(atom)
                if level == "match-all":
                        matches = set()
                        for db in self._dbs:
                                if hasattr(db, "xmatch"):
                                        matches.update(db.xmatch(level, atom))
                                else:
                                        matches.update(db.match(atom))
                        result = list(x for x in matches if portage.cpv_getkey(x) == cp)
                        db._cpv_sort_ascending(result)
                elif level == "match-visible":
                        matches = set()
                        for db in self._dbs:
                                if hasattr(db, "xmatch"):
                                        matches.update(db.xmatch(level, atom))
                                else:
                                        db_keys = list(db._aux_cache_keys)
                                        for cpv in db.match(atom):
                                                metadata = izip(db_keys,
                                                        db.aux_get(cpv, db_keys))
                                                if not self._visible(db, cpv, metadata):
                                                        continue
                                                matches.add(cpv)
                        result = list(x for x in matches if portage.cpv_getkey(x) == cp)
                        db._cpv_sort_ascending(result)
                elif level == "bestmatch-visible":
                        result = None
                        for db in self._dbs:
                                if hasattr(db, "xmatch"):
                                        cpv = db.xmatch("bestmatch-visible", atom)
                                        if not cpv or portage.cpv_getkey(cpv) != cp:
                                                continue
                                        if not result or cpv == portage.best([cpv, result]):
                                                result = cpv
                                else:
                                        db_keys = Package.metadata_keys
                                        # break out of this loop with highest visible
                                        # match, checked in descending order
                                        for cpv in reversed(db.match(atom)):
                                                if portage.cpv_getkey(cpv) != cp:
                                                        continue
                                                metadata = izip(db_keys,
                                                        db.aux_get(cpv, db_keys))
                                                if not self._visible(db, cpv, metadata):
                                                        continue
                                                if not result or cpv == portage.best([cpv, result]):
                                                        result = cpv
                                                break
                else:
                        raise NotImplementedError(level)
                return result

        def execute(self,searchkey):
                """Performs the search for the supplied search key"""
                match_category = 0
                self.searchkey=searchkey
                self.packagematches = []
                if self.searchdesc:
                        self.searchdesc=1
                        self.matches = {"pkg":[], "desc":[], "set":[]}
                else:
                        self.searchdesc=0
                        self.matches = {"pkg":[], "set":[]}
                print "Searching...   ",

                regexsearch = False
                if self.searchkey.startswith('%'):
                        regexsearch = True
                        self.searchkey = self.searchkey[1:]
                if self.searchkey.startswith('@'):
                        match_category = 1
                        self.searchkey = self.searchkey[1:]
                if regexsearch:
                        self.searchre=re.compile(self.searchkey,re.I)
                else:
                        self.searchre=re.compile(re.escape(self.searchkey), re.I)
                for package in self.portdb.cp_all():
                        self.spinner.update()

                        if match_category:
                                match_string  = package[:]
                        else:
                                match_string  = package.split("/")[-1]

                        masked=0
                        if self.searchre.search(match_string):
                                if not self.portdb.xmatch("match-visible", package):
                                        masked=1
                                self.matches["pkg"].append([package,masked])
                        elif self.searchdesc: # DESCRIPTION searching
                                full_package = self.portdb.xmatch("bestmatch-visible", package)
                                if not full_package:
                                        #no match found; we don't want to query description
                                        full_package = portage.best(
                                                self.portdb.xmatch("match-all", package))
                                        if not full_package:
                                                continue
                                        else:
                                                masked=1
                                try:
                                        full_desc = self.portdb.aux_get(
                                                full_package, ["DESCRIPTION"])[0]
                                except KeyError:
                                        print "emerge: search: aux_get() failed, skipping"
                                        continue
                                if self.searchre.search(full_desc):
                                        self.matches["desc"].append([full_package,masked])

                self.sdict = self.setconfig.getSets()
                for setname in self.sdict:
                        self.spinner.update()
                        if match_category:
                                match_string = setname
                        else:
                                match_string = setname.split("/")[-1]
                        
                        if self.searchre.search(match_string):
                                self.matches["set"].append([setname, False])
                        elif self.searchdesc:
                                if self.searchre.search(
                                        self.sdict[setname].getMetadata("DESCRIPTION")):
                                        self.matches["set"].append([setname, False])
                        
                self.mlen=0
                for mtype in self.matches:
                        self.matches[mtype].sort()
                        self.mlen += len(self.matches[mtype])

        def addCP(self, cp):
                if not self.portdb.xmatch("match-all", cp):
                        return
                masked = 0
                if not self.portdb.xmatch("bestmatch-visible", cp):
                        masked = 1
                self.matches["pkg"].append([cp, masked])
                self.mlen += 1

        def output(self):
                """Outputs the results of the search."""
                print "\b\b  \n[ Results for search key : "+white(self.searchkey)+" ]"
                print "[ Applications found : "+white(str(self.mlen))+" ]"
                print " "
                vardb = self.vartree.dbapi
                for mtype in self.matches:
                        for match,masked in self.matches[mtype]:
                                full_package = None
                                if mtype == "pkg":
                                        catpack = match
                                        full_package = self.portdb.xmatch(
                                                "bestmatch-visible", match)
                                        if not full_package:
                                                #no match found; we don't want to query description
                                                masked=1
                                                full_package = portage.best(
                                                        self.portdb.xmatch("match-all",match))
                                elif mtype == "desc":
                                        full_package = match
                                        match        = portage.cpv_getkey(match)
                                elif mtype == "set":
                                        print green("*")+"  "+white(match)
                                        print "     ", darkgreen("Description:")+"  ", self.sdict[match].getMetadata("DESCRIPTION")
                                        print
                                if full_package:
                                        try:
                                                desc, homepage, license = self.portdb.aux_get(
                                                        full_package, ["DESCRIPTION","HOMEPAGE","LICENSE"])
                                        except KeyError:
                                                print "emerge: search: aux_get() failed, skipping"
                                                continue
                                        if masked:
                                                print green("*")+"  "+white(match)+" "+red("[ Masked ]")
                                        else:
                                                print green("*")+"  "+white(match)
                                        myversion = self.getVersion(full_package, search.VERSION_RELEASE)

                                        mysum = [0,0]
                                        file_size_str = None
                                        mycat = match.split("/")[0]
                                        mypkg = match.split("/")[1]
                                        mycpv = match + "-" + myversion
                                        myebuild = self.portdb.findname(mycpv)
                                        if myebuild:
                                                pkgdir = os.path.dirname(myebuild)
                                                from portage import manifest
                                                mf = manifest.Manifest(
                                                        pkgdir, self.settings["DISTDIR"])
                                                try:
                                                        uri_map = self.portdb.getFetchMap(mycpv)
                                                except portage.exception.InvalidDependString, e:
                                                        file_size_str = "Unknown (%s)" % (e,)
                                                        del e
                                                else:
                                                        try:
                                                                mysum[0] = mf.getDistfilesSize(uri_map)
                                                        except KeyError, e:
                                                                file_size_str = "Unknown (missing " + \
                                                                        "digest for %s)" % (e,)
                                                                del e

                                        available = False
                                        for db in self._dbs:
                                                if db is not vardb and \
                                                        db.cpv_exists(mycpv):
                                                        available = True
                                                        if not myebuild and hasattr(db, "bintree"):
                                                                myebuild = db.bintree.getname(mycpv)
                                                                try:
                                                                        mysum[0] = os.stat(myebuild).st_size
                                                                except OSError:
                                                                        myebuild = None
                                                        break

                                        if myebuild and file_size_str is None:
                                                mystr = str(mysum[0] / 1024)
                                                mycount = len(mystr)
                                                while (mycount > 3):
                                                        mycount -= 3
                                                        mystr = mystr[:mycount] + "," + mystr[mycount:]
                                                file_size_str = mystr + " kB"

                                        if self.verbose:
                                                if available:
                                                        print "     ", darkgreen("Latest version available:"),myversion
                                                print "     ", self.getInstallationStatus(mycat+'/'+mypkg)
                                                if myebuild:
                                                        print "      %s %s" % \
                                                                (darkgreen("Size of files:"), file_size_str)
                                                print "     ", darkgreen("Homepage:")+"     ",homepage
                                                print "     ", darkgreen("Description:")+"  ",desc
                                                print "     ", darkgreen("License:")+"      ",license
                                                print
        #
        # private interface
        #
        def getInstallationStatus(self,package):
                installed_package = self.vartree.dep_bestmatch(package)
                result = ""
                version = self.getVersion(installed_package,search.VERSION_RELEASE)
                if len(version) > 0:
                        result = darkgreen("Latest version installed:")+" "+version
                else:
                        result = darkgreen("Latest version installed:")+" [ Not Installed ]"
                return result

        def getVersion(self,full_package,detail):
                if len(full_package) > 1:
                        package_parts = portage.catpkgsplit(full_package)
                        if detail == search.VERSION_RELEASE and package_parts[3] != 'r0':
                                result = package_parts[2]+ "-" + package_parts[3]
                        else:
                                result = package_parts[2]
                else:
                        result = ""
                return result

class RootConfig(object):
        """This is used internally by depgraph to track information about a
        particular $ROOT."""

        pkg_tree_map = {
                "ebuild"    : "porttree",
                "binary"    : "bintree",
                "installed" : "vartree"
        }

        tree_pkg_map = {}
        for k, v in pkg_tree_map.iteritems():
                tree_pkg_map[v] = k

        def __init__(self, settings, trees, setconfig):
                self.trees = trees
                self.settings = settings
                self.iuse_implicit = tuple(sorted(settings._get_implicit_iuse()))
                self.root = self.settings["ROOT"]
                self.setconfig = setconfig
                self.sets = self.setconfig.getSets()
                self.visible_pkgs = PackageVirtualDbapi(self.settings)

def create_world_atom(pkg, args_set, root_config):
        """Create a new atom for the world file if one does not exist.  If the
        argument atom is precise enough to identify a specific slot then a slot
        atom will be returned. Atoms that are in the system set may also be stored
        in world since system atoms can only match one slot while world atoms can
        be greedy with respect to slots.  Unslotted system packages will not be
        stored in world."""

        arg_atom = args_set.findAtomForPackage(pkg)
        if not arg_atom:
                return None
        cp = portage.dep_getkey(arg_atom)
        new_world_atom = cp
        sets = root_config.sets
        portdb = root_config.trees["porttree"].dbapi
        vardb = root_config.trees["vartree"].dbapi
        available_slots = set(portdb.aux_get(cpv, ["SLOT"])[0] \
                for cpv in portdb.match(cp))
        slotted = len(available_slots) > 1 or \
                (len(available_slots) == 1 and "0" not in available_slots)
        if not slotted:
                # check the vdb in case this is multislot
                available_slots = set(vardb.aux_get(cpv, ["SLOT"])[0] \
                        for cpv in vardb.match(cp))
                slotted = len(available_slots) > 1 or \
                        (len(available_slots) == 1 and "0" not in available_slots)
        if slotted and arg_atom != cp:
                # If the user gave a specific atom, store it as a
                # slot atom in the world file.
                slot_atom = pkg.slot_atom

                # For USE=multislot, there are a couple of cases to
                # handle here:
                #
                # 1) SLOT="0", but the real SLOT spontaneously changed to some
                #    unknown value, so just record an unslotted atom.
                #
                # 2) SLOT comes from an installed package and there is no
                #    matching SLOT in the portage tree.
                #
                # Make sure that the slot atom is available in either the
                # portdb or the vardb, since otherwise the user certainly
                # doesn't want the SLOT atom recorded in the world file
                # (case 1 above).  If it's only available in the vardb,
                # the user may be trying to prevent a USE=multislot
                # package from being removed by --depclean (case 2 above).

                mydb = portdb
                if not portdb.match(slot_atom):
                        # SLOT seems to come from an installed multislot package
                        mydb = vardb
                # If there is no installed package matching the SLOT atom,
                # it probably changed SLOT spontaneously due to USE=multislot,
                # so just record an unslotted atom.
                if vardb.match(slot_atom):
                        # Now verify that the argument is precise
                        # enough to identify a specific slot.
                        matches = mydb.match(arg_atom)
                        matched_slots = set()
                        for cpv in matches:
                                matched_slots.add(mydb.aux_get(cpv, ["SLOT"])[0])
                        if len(matched_slots) == 1:
                                new_world_atom = slot_atom

        if new_world_atom == sets["world"].findAtomForPackage(pkg):
                # Both atoms would be identical, so there's nothing to add.
                return None
        if not slotted:
                # Unlike world atoms, system atoms are not greedy for slots, so they
                # can't be safely excluded from world if they are slotted.
                system_atom = sets["system"].findAtomForPackage(pkg)
                if system_atom:
                        if not portage.dep_getkey(system_atom).startswith("virtual/"):
                                return None
                        # System virtuals aren't safe to exclude from world since they can
                        # match multiple old-style virtuals but only one of them will be
                        # pulled in by update or depclean.
                        providers = portdb.mysettings.getvirtuals().get(
                                portage.dep_getkey(system_atom))
                        if providers and len(providers) == 1 and providers[0] == cp:
                                return None
        return new_world_atom

def filter_iuse_defaults(iuse):
        for flag in iuse:
                if flag.startswith("+") or flag.startswith("-"):
                        yield flag[1:]
                else:
                        yield flag

class SlotObject(object):
        __slots__ = ("__weakref__",)

        def __init__(self, **kwargs):
                classes = [self.__class__]
                while classes:
                        c = classes.pop()
                        if c is SlotObject:
                                continue
                        classes.extend(c.__bases__)
                        slots = getattr(c, "__slots__", None)
                        if not slots:
                                continue
                        for myattr in slots:
                                myvalue = kwargs.get(myattr, None)
                                setattr(self, myattr, myvalue)

        def copy(self):
                """
                Create a new instance and copy all attributes
                defined from __slots__ (including those from
                inherited classes).
                """
                obj = self.__class__()

                classes = [self.__class__]
                while classes:
                        c = classes.pop()
                        if c is SlotObject:
                                continue
                        classes.extend(c.__bases__)
                        slots = getattr(c, "__slots__", None)
                        if not slots:
                                continue
                        for myattr in slots:
                                setattr(obj, myattr, getattr(self, myattr))

                return obj

class AbstractDepPriority(SlotObject):
        __slots__ = ("buildtime", "runtime", "runtime_post")

        def __lt__(self, other):
                return self.__int__() < other

        def __le__(self, other):
                return self.__int__() <= other

        def __eq__(self, other):
                return self.__int__() == other

        def __ne__(self, other):
                return self.__int__() != other

        def __gt__(self, other):
                return self.__int__() > other

        def __ge__(self, other):
                return self.__int__() >= other

        def copy(self):
                import copy
                return copy.copy(self)

class DepPriority(AbstractDepPriority):
        """
                This class generates an integer priority level based of various
                attributes of the dependency relationship.  Attributes can be assigned
                at any time and the new integer value will be generated on calls to the
                __int__() method.  Rich comparison operators are supported.

                The boolean attributes that affect the integer value are "satisfied",
                "buildtime", "runtime", and "system".  Various combinations of
                attributes lead to the following priority levels:

                Combination of properties           Priority  Category

                not satisfied and buildtime            0       HARD
                not satisfied and runtime             -1       MEDIUM
                not satisfied and runtime_post        -2       MEDIUM_SOFT
                satisfied and buildtime and rebuild   -3       SOFT
                satisfied and buildtime               -4       SOFT
                satisfied and runtime                 -5       SOFT
                satisfied and runtime_post            -6       SOFT
                (none of the above)                   -6       SOFT

                Several integer constants are defined for categorization of priority
                levels:

                MEDIUM   The upper boundary for medium dependencies.
                MEDIUM_SOFT   The upper boundary for medium-soft dependencies.
                SOFT     The upper boundary for soft dependencies.
                MIN      The lower boundary for soft dependencies.
        """
        __slots__ = ("satisfied", "rebuild")
        MEDIUM = -1
        MEDIUM_SOFT = -2
        SOFT   = -3
        MIN    = -6

        def __int__(self):
                if not self.satisfied:
                        if self.buildtime:
                                return 0
                        if self.runtime:
                                return -1
                        if self.runtime_post:
                                return -2
                if self.buildtime:
                        if self.rebuild:
                                return -3
                        return -4
                if self.runtime:
                        return -5
                if self.runtime_post:
                        return -6
                return -6

        def __str__(self):
                myvalue = self.__int__()
                if myvalue > self.MEDIUM:
                        return "hard"
                if myvalue > self.MEDIUM_SOFT:
                        return "medium"
                if myvalue > self.SOFT:
                        return "medium-soft"
                return "soft"

class BlockerDepPriority(DepPriority):
        __slots__ = ()
        def __int__(self):
                return 0

BlockerDepPriority.instance = BlockerDepPriority()

class UnmergeDepPriority(AbstractDepPriority):
        __slots__ = ("satisfied",)
        """
        Combination of properties           Priority  Category

        runtime                                0       HARD
        runtime_post                          -1       HARD
        buildtime                             -2       SOFT
        (none of the above)                   -2       SOFT
        """

        MAX    =  0
        SOFT   = -2
        MIN    = -2

        def __int__(self):
                if self.runtime:
                        return 0
                if self.runtime_post:
                        return -1
                if self.buildtime:
                        return -2
                return -2

        def __str__(self):
                myvalue = self.__int__()
                if myvalue > self.SOFT:
                        return "hard"
                return "soft"

class FakeVartree(portage.vartree):
        """This is implements an in-memory copy of a vartree instance that provides
        all the interfaces required for use by the depgraph.  The vardb is locked
        during the constructor call just long enough to read a copy of the
        installed package information.  This allows the depgraph to do it's
        dependency calculations without holding a lock on the vardb.  It also
        allows things like vardb global updates to be done in memory so that the
        user doesn't necessarily need write access to the vardb in cases where
        global updates are necessary (updates are performed when necessary if there
        is not a matching ebuild in the tree)."""
        def __init__(self, root_config, pkg_cache=None, acquire_lock=1):
                self._root_config = root_config
                if pkg_cache is None:
                        pkg_cache = {}
                real_vartree = root_config.trees["vartree"]
                portdb = root_config.trees["porttree"].dbapi
                self.root = real_vartree.root
                self.settings = real_vartree.settings
                mykeys = list(real_vartree.dbapi._aux_cache_keys)
                self._pkg_cache = pkg_cache
                self.dbapi = PackageVirtualDbapi(real_vartree.settings)
                vdb_path = os.path.join(self.root, portage.VDB_PATH)
                try:
                        # At least the parent needs to exist for the lock file.
                        portage.util.ensure_dirs(vdb_path)
                except portage.exception.PortageException:
                        pass
                vdb_lock = None
                try:
                        if acquire_lock and os.access(vdb_path, os.W_OK):
                                vdb_lock = portage.locks.lockdir(vdb_path)
                        real_dbapi = real_vartree.dbapi
                        slot_counters = {}
                        for cpv in real_dbapi.cpv_all():
                                cache_key = ("installed", self.root, cpv, "nomerge")
                                pkg = self._pkg_cache.get(cache_key)
                                if pkg is not None:
                                        metadata = pkg.metadata
                                else:
                                        metadata = dict(izip(mykeys, real_dbapi.aux_get(cpv, mykeys)))
                                myslot = metadata["SLOT"]
                                mycp = portage.dep_getkey(cpv)
                                myslot_atom = "%s:%s" % (mycp, myslot)
                                try:
                                        mycounter = long(metadata["COUNTER"])
                                except ValueError:
                                        mycounter = 0
                                        metadata["COUNTER"] = str(mycounter)
                                other_counter = slot_counters.get(myslot_atom, None)
                                if other_counter is not None:
                                        if other_counter > mycounter:
                                                continue
                                slot_counters[myslot_atom] = mycounter
                                if pkg is None:
                                        pkg = Package(built=True, cpv=cpv,
                                                installed=True, metadata=metadata,
                                                root_config=root_config, type_name="installed")
                                self._pkg_cache[pkg] = pkg
                                self.dbapi.cpv_inject(pkg)
                        real_dbapi.flush_cache()
                finally:
                        if vdb_lock:
                                portage.locks.unlockdir(vdb_lock)
                # Populate the old-style virtuals using the cached values.
                if not self.settings.treeVirtuals:
                        self.settings.treeVirtuals = portage.util.map_dictlist_vals(
                                portage.getCPFromCPV, self.get_all_provides())

                # Intialize variables needed for lazy cache pulls of the live ebuild
                # metadata.  This ensures that the vardb lock is released ASAP, without
                # being delayed in case cache generation is triggered.
                self._aux_get = self.dbapi.aux_get
                self.dbapi.aux_get = self._aux_get_wrapper
                self._match = self.dbapi.match
                self.dbapi.match = self._match_wrapper
                self._aux_get_history = set()
                self._portdb_keys = ["EAPI", "DEPEND", "RDEPEND", "PDEPEND"]
                self._portdb = portdb
                self._global_updates = None

        def _match_wrapper(self, cpv, use_cache=1):
                """
                Make sure the metadata in Package instances gets updated for any
                cpv that is returned from a match() call, since the metadata can
                be accessed directly from the Package instance instead of via
                aux_get().
                """
                matches = self._match(cpv, use_cache=use_cache)
                for cpv in matches:
                        if cpv in self._aux_get_history:
                                continue
                        self._aux_get_wrapper(cpv, [])
                return matches

        def _aux_get_wrapper(self, pkg, wants):
                if pkg in self._aux_get_history:
                        return self._aux_get(pkg, wants)
                self._aux_get_history.add(pkg)
                try:
                        # Use the live ebuild metadata if possible.
                        live_metadata = dict(izip(self._portdb_keys,
                                self._portdb.aux_get(pkg, self._portdb_keys)))
                        if not portage.eapi_is_supported(live_metadata["EAPI"]):
                                raise KeyError(pkg)
                        self.dbapi.aux_update(pkg, live_metadata)
                except (KeyError, portage.exception.PortageException):
                        if self._global_updates is None:
                                self._global_updates = \
                                        grab_global_updates(self._portdb.porttree_root)
                        perform_global_updates(
                                pkg, self.dbapi, self._global_updates)
                return self._aux_get(pkg, wants)

        def sync(self, acquire_lock=1):
                """
                Call this method to synchronize state with the real vardb
                after one or more packages may have been installed or
                uninstalled.
                """
                vdb_path = os.path.join(self.root, portage.VDB_PATH)
                try:
                        # At least the parent needs to exist for the lock file.
                        portage.util.ensure_dirs(vdb_path)
                except portage.exception.PortageException:
                        pass
                vdb_lock = None
                try:
                        if acquire_lock and os.access(vdb_path, os.W_OK):
                                vdb_lock = portage.locks.lockdir(vdb_path)
                        self._sync()
                finally:
                        if vdb_lock:
                                portage.locks.unlockdir(vdb_lock)

        def _sync(self):

                real_vardb = self._root_config.trees["vartree"].dbapi
                current_cpv_set = frozenset(real_vardb.cpv_all())
                pkg_vardb = self.dbapi
                aux_get_history = self._aux_get_history

                # Remove any packages that have been uninstalled.
                for pkg in list(pkg_vardb):
                        if pkg.cpv not in current_cpv_set:
                                pkg_vardb.cpv_remove(pkg)
                                aux_get_history.discard(pkg.cpv)

                # Validate counters and timestamps.
                slot_counters = {}
                root = self.root
                validation_keys = ["COUNTER", "_mtime_"]
                for cpv in current_cpv_set:

                        pkg_hash_key = ("installed", root, cpv, "nomerge")
                        pkg = pkg_vardb.get(pkg_hash_key)
                        if pkg is not None:
                                counter, mtime = real_vardb.aux_get(cpv, validation_keys)

                                if counter != pkg.metadata["COUNTER"] or \
                                        mtime != pkg.mtime:
                                        pkg_vardb.cpv_remove(pkg)
                                        aux_get_history.discard(pkg.cpv)
                                        pkg = None

                        if pkg is None:
                                pkg = self._pkg(cpv)

                        other_counter = slot_counters.get(pkg.slot_atom)
                        if other_counter is not None:
                                if other_counter > pkg.counter:
                                        continue

                        slot_counters[pkg.slot_atom] = pkg.counter
                        pkg_vardb.cpv_inject(pkg)

                real_vardb.flush_cache()

        def _pkg(self, cpv):
                root_config = self._root_config
                real_vardb = root_config.trees["vartree"].dbapi
                db_keys = list(real_vardb._aux_cache_keys)
                pkg = Package(cpv=cpv, installed=True,
                        metadata=izip(db_keys, real_vardb.aux_get(cpv, db_keys)),
                        root_config=root_config,
                        type_name="installed")
                return pkg

def grab_global_updates(portdir):
        from portage.update import grab_updates, parse_updates
        updpath = os.path.join(portdir, "profiles", "updates")
        try:
                rawupdates = grab_updates(updpath)
        except portage.exception.DirectoryNotFound:
                rawupdates = []
        upd_commands = []
        for mykey, mystat, mycontent in rawupdates:
                commands, errors = parse_updates(mycontent)
                upd_commands.extend(commands)
        return upd_commands

def perform_global_updates(mycpv, mydb, mycommands):
        from portage.update import update_dbentries
        aux_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
        aux_dict = dict(izip(aux_keys, mydb.aux_get(mycpv, aux_keys)))
        updates = update_dbentries(mycommands, aux_dict)
        if updates:
                mydb.aux_update(mycpv, updates)

def visible(pkgsettings, pkg):
        """
        Check if a package is visible. This can raise an InvalidDependString
        exception if LICENSE is invalid.
        TODO: optionally generate a list of masking reasons
        @rtype: Boolean
        @returns: True if the package is visible, False otherwise.
        """
        if not pkg.metadata["SLOT"]:
                return False
        if pkg.built and not pkg.installed and "CHOST" in pkg.metadata:
                if not pkgsettings._accept_chost(pkg):
                        return False
        eapi = pkg.metadata["EAPI"]
        if not portage.eapi_is_supported(eapi):
                return False
        if not pkg.installed:
                if portage._eapi_is_deprecated(eapi):
                        return False
                if pkgsettings._getMissingKeywords(pkg.cpv, pkg.metadata):
                        return False
        if pkgsettings._getMaskAtom(pkg.cpv, pkg.metadata):
                return False
        if pkgsettings._getProfileMaskAtom(pkg.cpv, pkg.metadata):
                return False
        try:
                if pkgsettings._getMissingLicenses(pkg.cpv, pkg.metadata):
                        return False
        except portage.exception.InvalidDependString:
                return False
        return True

def get_masking_status(pkg, pkgsettings, root_config):

        mreasons = portage.getmaskingstatus(
                pkg, settings=pkgsettings,
                portdb=root_config.trees["porttree"].dbapi)

        if pkg.built and not pkg.installed and "CHOST" in pkg.metadata:
                if not pkgsettings._accept_chost(pkg):
                        mreasons.append("CHOST: %s" % \
                                pkg.metadata["CHOST"])

        if not pkg.metadata["SLOT"]:
                mreasons.append("invalid: SLOT is undefined")

        return mreasons

def get_mask_info(root_config, cpv, pkgsettings,
        db, pkg_type, built, installed, db_keys):
        eapi_masked = False
        try:
                metadata = dict(izip(db_keys,
                        db.aux_get(cpv, db_keys)))
        except KeyError:
                metadata = None
        if metadata and not built:
                pkgsettings.setcpv(cpv, mydb=metadata)
                metadata["USE"] = pkgsettings["PORTAGE_USE"]
        if metadata is None:
                mreasons = ["corruption"]
        else:
                pkg = Package(type_name=pkg_type, root_config=root_config,
                        cpv=cpv, built=built, installed=installed, metadata=metadata)
                mreasons = get_masking_status(pkg, pkgsettings, root_config)
        return metadata, mreasons

def show_masked_packages(masked_packages):
        shown_licenses = set()
        shown_comments = set()
        # Maybe there is both an ebuild and a binary. Only
        # show one of them to avoid redundant appearance.
        shown_cpvs = set()
        have_eapi_mask = False
        for (root_config, pkgsettings, cpv,
                metadata, mreasons) in masked_packages:
                if cpv in shown_cpvs:
                        continue
                shown_cpvs.add(cpv)
                comment, filename = None, None
                if "package.mask" in mreasons:
                        comment, filename = \
                                portage.getmaskingreason(
                                cpv, metadata=metadata,
                                settings=pkgsettings,
                                portdb=root_config.trees["porttree"].dbapi,
                                return_location=True)
                missing_licenses = []
                if metadata:
                        if not portage.eapi_is_supported(metadata["EAPI"]):
                                have_eapi_mask = True
                        try:
                                missing_licenses = \
                                        pkgsettings._getMissingLicenses(
                                                cpv, metadata)
                        except portage.exception.InvalidDependString:
                                # This will have already been reported
                                # above via mreasons.
                                pass

                print "- "+cpv+" (masked by: "+", ".join(mreasons)+")"
                if comment and comment not in shown_comments:
                        print filename+":"
                        print comment
                        shown_comments.add(comment)
                portdb = root_config.trees["porttree"].dbapi
                for l in missing_licenses:
                        l_path = portdb.findLicensePath(l)
                        if l in shown_licenses:
                                continue
                        msg = ("A copy of the '%s' license" + \
                        " is located at '%s'.") % (l, l_path)
                        print msg
                        print
                        shown_licenses.add(l)
        return have_eapi_mask

class Task(SlotObject):
        __slots__ = ("_hash_key", "_hash_value")

        def _get_hash_key(self):
                hash_key = getattr(self, "_hash_key", None)
                if hash_key is None:
                        raise NotImplementedError(self)
                return hash_key

        def __eq__(self, other):
                return self._get_hash_key() == other

        def __ne__(self, other):
                return self._get_hash_key() != other

        def __hash__(self):
                hash_value = getattr(self, "_hash_value", None)
                if hash_value is None:
                        self._hash_value = hash(self._get_hash_key())
                return self._hash_value

        def __len__(self):
                return len(self._get_hash_key())

        def __getitem__(self, key):
                return self._get_hash_key()[key]

        def __iter__(self):
                return iter(self._get_hash_key())

        def __contains__(self, key):
                return key in self._get_hash_key()

        def __str__(self):
                return str(self._get_hash_key())

class Blocker(Task):

        __hash__ = Task.__hash__
        __slots__ = ("root", "atom", "cp", "eapi", "satisfied")

        def __init__(self, **kwargs):
                Task.__init__(self, **kwargs)
                self.cp = portage.dep_getkey(self.atom)

        def _get_hash_key(self):
                hash_key = getattr(self, "_hash_key", None)
                if hash_key is None:
                        self._hash_key = \
                                ("blocks", self.root, self.atom, self.eapi)
                return self._hash_key

class Package(Task):

        __hash__ = Task.__hash__
        __slots__ = ("built", "cpv", "depth",
                "installed", "metadata", "onlydeps", "operation",
                "root_config", "type_name",
                "category", "counter", "cp", "cpv_split",
                "inherited", "iuse", "mtime",
                "pf", "pv_split", "root", "slot", "slot_atom", "use")

        metadata_keys = [
                "CHOST", "COUNTER", "DEPEND", "EAPI",
                "INHERITED", "IUSE", "KEYWORDS",
                "LICENSE", "PDEPEND", "PROVIDE", "RDEPEND",
                "repository", "PROPERTIES", "RESTRICT", "SLOT", "USE", "_mtime_"]

        def __init__(self, **kwargs):
                Task.__init__(self, **kwargs)
                self.root = self.root_config.root
                self.metadata = _PackageMetadataWrapper(self, self.metadata)
                self.cp = portage.cpv_getkey(self.cpv)
                self.slot_atom = portage.dep.Atom("%s:%s" % (self.cp, self.slot))
                self.category, self.pf = portage.catsplit(self.cpv)
                self.cpv_split = portage.catpkgsplit(self.cpv)
                self.pv_split = self.cpv_split[1:]

        class _use(object):

                __slots__ = ("__weakref__", "enabled")

                def __init__(self, use):
                        self.enabled = frozenset(use)

        class _iuse(object):

                __slots__ = ("__weakref__", "all", "enabled", "disabled", "iuse_implicit", "regex", "tokens")

                def __init__(self, tokens, iuse_implicit):
                        self.tokens = tuple(tokens)
                        self.iuse_implicit = iuse_implicit
                        enabled = []
                        disabled = []
                        other = []
                        for x in tokens:
                                prefix = x[:1]
                                if prefix == "+":
                                        enabled.append(x[1:])
                                elif prefix == "-":
                                        disabled.append(x[1:])
                                else:
                                        other.append(x)
                        self.enabled = frozenset(enabled)
                        self.disabled = frozenset(disabled)
                        self.all = frozenset(chain(enabled, disabled, other))

                def __getattribute__(self, name):
                        if name == "regex":
                                try:
                                        return object.__getattribute__(self, "regex")
                                except AttributeError:
                                        all = object.__getattribute__(self, "all")
                                        iuse_implicit = object.__getattribute__(self, "iuse_implicit")
                                        # Escape anything except ".*" which is supposed
                                        # to pass through from _get_implicit_iuse()
                                        regex = (re.escape(x) for x in chain(all, iuse_implicit))
                                        regex = "^(%s)$" % "|".join(regex)
                                        regex = regex.replace("\\.\\*", ".*")
                                        self.regex = re.compile(regex)
                        return object.__getattribute__(self, name)

        def _get_hash_key(self):
                hash_key = getattr(self, "_hash_key", None)
                if hash_key is None:
                        if self.operation is None:
                                self.operation = "merge"
                                if self.onlydeps or self.installed:
                                        self.operation = "nomerge"
                        self._hash_key = \
                                (self.type_name, self.root, self.cpv, self.operation)
                return self._hash_key

        def __cmp__(self, other):
                if self > other:
                        return 1
                elif self < other:
                        return -1
                return 0

        def __lt__(self, other):
                if other.cp != self.cp:
                        return False
                if portage.pkgcmp(self.pv_split, other.pv_split) < 0:
                        return True
                return False

        def __le__(self, other):
                if other.cp != self.cp:
                        return False
                if portage.pkgcmp(self.pv_split, other.pv_split) <= 0:
                        return True
                return False

        def __gt__(self, other):
                if other.cp != self.cp:
                        return False
                if portage.pkgcmp(self.pv_split, other.pv_split) > 0:
                        return True
                return False

        def __ge__(self, other):
                if other.cp != self.cp:
                        return False
                if portage.pkgcmp(self.pv_split, other.pv_split) >= 0:
                        return True
                return False

_all_metadata_keys = set(x for x in portage.auxdbkeys \
        if not x.startswith("UNUSED_"))
_all_metadata_keys.discard("CDEPEND")
_all_metadata_keys.update(Package.metadata_keys)

from portage.cache.mappings import slot_dict_class
_PackageMetadataWrapperBase = slot_dict_class(_all_metadata_keys)

class _PackageMetadataWrapper(_PackageMetadataWrapperBase):
        """
        Detect metadata updates and synchronize Package attributes.
        """

        __slots__ = ("_pkg",)
        _wrapped_keys = frozenset(
                ["COUNTER", "INHERITED", "IUSE", "SLOT", "USE", "_mtime_"])

        def __init__(self, pkg, metadata):
                _PackageMetadataWrapperBase.__init__(self)
                self._pkg = pkg
                self.update(metadata)

        def __setitem__(self, k, v):
                _PackageMetadataWrapperBase.__setitem__(self, k, v)
                if k in self._wrapped_keys:
                        getattr(self, "_set_" + k.lower())(k, v)

        def _set_inherited(self, k, v):
                if isinstance(v, basestring):
                        v = frozenset(v.split())
                self._pkg.inherited = v

        def _set_iuse(self, k, v):
                self._pkg.iuse = self._pkg._iuse(
                        v.split(), self._pkg.root_config.iuse_implicit)

        def _set_slot(self, k, v):
                self._pkg.slot = v

        def _set_use(self, k, v):
                self._pkg.use = self._pkg._use(v.split())

        def _set_counter(self, k, v):
                if isinstance(v, basestring):
                        try:
                                v = int(v.strip())
                        except ValueError:
                                v = 0
                self._pkg.counter = v

        def _set__mtime_(self, k, v):
                if isinstance(v, basestring):
                        try:
                                v = float(v.strip())
                        except ValueError:
                                v = 0
                self._pkg.mtime = v

class EbuildFetchonly(SlotObject):

        __slots__ = ("fetch_all", "pkg", "pretend", "settings")

        def execute(self):
                # To spawn pkg_nofetch requires PORTAGE_BUILDDIR for
                # ensuring sane $PWD (bug #239560) and storing elog
                # messages. Use a private temp directory, in order
                # to avoid locking the main one.
                settings = self.settings
                global_tmpdir = settings["PORTAGE_TMPDIR"]
                from tempfile import mkdtemp
                try:
                        private_tmpdir = mkdtemp("", "._portage_fetch_.", global_tmpdir)
                except OSError, e:
                        if e.errno != portage.exception.PermissionDenied.errno:
                                raise
                        raise portage.exception.PermissionDenied(global_tmpdir)
                settings["PORTAGE_TMPDIR"] = private_tmpdir
                settings.backup_changes("PORTAGE_TMPDIR")
                try:
                        retval = self._execute()
                finally:
                        settings["PORTAGE_TMPDIR"] = global_tmpdir
                        settings.backup_changes("PORTAGE_TMPDIR")
                        shutil.rmtree(private_tmpdir)
                return retval

        def _execute(self):
                settings = self.settings
                pkg = self.pkg
                root_config = pkg.root_config
                portdb = root_config.trees["porttree"].dbapi
                ebuild_path = portdb.findname(pkg.cpv)
                settings.setcpv(pkg)
                debug = settings.get("PORTAGE_DEBUG") == "1"
                use_cache = 1 # always true
                portage.doebuild_environment(ebuild_path, "fetch",
                        root_config.root, settings, debug, use_cache, portdb)
                portage.prepare_build_dirs(self.pkg.root, self.settings, 0)

                retval = portage.doebuild(ebuild_path, "fetch",
                        self.settings["ROOT"], self.settings, debug=debug,
                        listonly=self.pretend, fetchonly=1, fetchall=self.fetch_all,
                        mydbapi=portdb, tree="porttree")

                if retval != os.EX_OK:
                        msg = "Fetch failed for '%s'" % (pkg.cpv,)
                        eerror(msg, phase="unpack", key=pkg.cpv)

                portage.elog.elog_process(self.pkg.cpv, self.settings)
                return retval

class AsynchronousTask(SlotObject):
        """
        Subclasses override _wait() and _poll() so that calls
        to public methods can be wrapped for implementing
        hooks such as exit listener notification.

        Sublasses should call self.wait() to notify exit listeners after
        the task is complete and self.returncode has been set.
        """

        __slots__ = ("background", "cancelled", "returncode") + \
                ("_exit_listeners", "_exit_listener_stack", "_start_listeners")

        def start(self):
                """
                Start an asynchronous task and then return as soon as possible.
                """
                self._start()
                self._start_hook()

        def _start(self):
                raise NotImplementedError(self)

        def isAlive(self):
                return self.returncode is None

        def poll(self):
                self._wait_hook()
                return self._poll()

        def _poll(self):
                return self.returncode

        def wait(self):
                if self.returncode is None:
                        self._wait()
                self._wait_hook()
                return self.returncode

        def _wait(self):
                return self.returncode

        def cancel(self):
                self.cancelled = True
                self.wait()

        def addStartListener(self, f):
                """
                The function will be called with one argument, a reference to self.
                """
                if self._start_listeners is None:
                        self._start_listeners = []
                self._start_listeners.append(f)

        def removeStartListener(self, f):
                if self._start_listeners is None:
                        return
                self._start_listeners.remove(f)

        def _start_hook(self):
                if self._start_listeners is not None:
                        start_listeners = self._start_listeners
                        self._start_listeners = None

                        for f in start_listeners:
                                f(self)

        def addExitListener(self, f):
                """
                The function will be called with one argument, a reference to self.
                """
                if self._exit_listeners is None:
                        self._exit_listeners = []
                self._exit_listeners.append(f)

        def removeExitListener(self, f):
                if self._exit_listeners is None:
                        if self._exit_listener_stack is not None:
                                self._exit_listener_stack.remove(f)
                        return
                self._exit_listeners.remove(f)

        def _wait_hook(self):
                """
                Call this method after the task completes, just before returning
                the returncode from wait() or poll(). This hook is
                used to trigger exit listeners when the returncode first
                becomes available.
                """
                if self.returncode is not None and \
                        self._exit_listeners is not None:

                        # This prevents recursion, in case one of the
                        # exit handlers triggers this method again by
                        # calling wait(). Use a stack that gives
                        # removeExitListener() an opportunity to consume
                        # listeners from the stack, before they can get
                        # called below. This is necessary because a call
                        # to one exit listener may result in a call to
                        # removeExitListener() for another listener on
                        # the stack. That listener needs to be removed
                        # from the stack since it would be inconsistent
                        # to call it after it has been been passed into
                        # removeExitListener().
                        self._exit_listener_stack = self._exit_listeners
                        self._exit_listeners = None

                        self._exit_listener_stack.reverse()
                        while self._exit_listener_stack:
                                self._exit_listener_stack.pop()(self)

class PipeReader(AsynchronousTask):

        """
        Reads output from one or more files and saves it in memory,
        for retrieval via the getvalue() method. This is driven by
        the scheduler's poll() loop, so it runs entirely within the
        current process.
        """

        __slots__ = ("input_files", "scheduler",) + \
                ("pid", "_read_data", "_registered", "_reg_ids")

        _bufsize = 4096

        def _start(self):
                self._reg_ids = set()
                self._read_data = []
                for k, f in self.input_files.iteritems():
                        fcntl.fcntl(f.fileno(), fcntl.F_SETFL,
                                fcntl.fcntl(f.fileno(), fcntl.F_GETFL) | os.O_NONBLOCK)
                        self._reg_ids.add(self.scheduler.register(f.fileno(),
                                PollConstants.POLLIN, self._output_handler))
                self._registered = True

        def isAlive(self):
                return self._registered

        def _wait(self):
                if self.returncode is not None:
                        return self.returncode

                if self._registered:
                        self.scheduler.schedule(self._reg_ids)
                        self._unregister()

                self.returncode = os.EX_OK
                return self.returncode

        def getvalue(self):
                """Retrieve the entire contents"""
                return "".join(self._read_data)

        def close(self):
                """Free the memory buffer."""
                self._read_data = None

        def _output_handler(self, fd, event):
                files = self.input_files
                for f in files.itervalues():
                        if fd == f.fileno():
                                break

                buf = array.array('B')
                try:
                        buf.fromfile(f, self._bufsize)
                except EOFError:
                        pass

                if buf:
                        self._read_data.append(buf.tostring())
                else:
                        self._unregister()
                        self.wait()

                return self._registered

        def _unregister(self):
                """
                Unregister from the scheduler and close open files.
                """

                self._registered = False

                if self._reg_ids is not None:
                        for reg_id in self._reg_ids:
                                self.scheduler.unregister(reg_id)
                        self._reg_ids = None

                if self.input_files is not None:
                        for f in self.input_files.itervalues():
                                f.close()
                        self.input_files = None

class CompositeTask(AsynchronousTask):

        __slots__ = ("scheduler",) + ("_current_task",)

        def isAlive(self):
                return self._current_task is not None

        def cancel(self):
                self.cancelled = True
                if self._current_task is not None:
                        self._current_task.cancel()

        def _poll(self):
                """
                This does a loop calling self._current_task.poll()
                repeatedly as long as the value of self._current_task
                keeps changing. It calls poll() a maximum of one time
                for a given self._current_task instance. This is useful
                since calling poll() on a task can trigger advance to
                the next task could eventually lead to the returncode
                being set in cases when polling only a single task would
                not have the same effect.
                """

                prev = None
                while True:
                        task = self._current_task
                        if task is None or task is prev:
                                # don't poll the same task more than once
                                break
                        task.poll()
                        prev = task

                return self.returncode

        def _wait(self):

                prev = None
                while True:
                        task = self._current_task
                        if task is None:
                                # don't wait for the same task more than once
                                break
                        if task is prev:
                                # Before the task.wait() method returned, an exit
                                # listener should have set self._current_task to either
                                # a different task or None. Something is wrong.
                                raise AssertionError("self._current_task has not " + \
                                        "changed since calling wait", self, task)
                        task.wait()
                        prev = task

                return self.returncode

        def _assert_current(self, task):
                """
                Raises an AssertionError if the given task is not the
                same one as self._current_task. This can be useful
                for detecting bugs.
                """
                if task is not self._current_task:
                        raise AssertionError("Unrecognized task: %s" % (task,))

        def _default_exit(self, task):
                """
                Calls _assert_current() on the given task and then sets the
                composite returncode attribute if task.returncode != os.EX_OK.
                If the task failed then self._current_task will be set to None.
                Subclasses can use this as a generic task exit callback.

                @rtype: int
                @returns: The task.returncode attribute.
                """
                self._assert_current(task)
                if task.returncode != os.EX_OK:
                        self.returncode = task.returncode
                        self._current_task = None
                return task.returncode

        def _final_exit(self, task):
                """
                Assumes that task is the final task of this composite task.
                Calls _default_exit() and sets self.returncode to the task's
                returncode and sets self._current_task to None.
                """
                self._default_exit(task)
                self._current_task = None
                self.returncode = task.returncode
                return self.returncode

        def _default_final_exit(self, task):
                """
                This calls _final_exit() and then wait().

                Subclasses can use this as a generic final task exit callback.

                """
                self._final_exit(task)
                return self.wait()

        def _start_task(self, task, exit_handler):
                """
                Register exit handler for the given task, set it
                as self._current_task, and call task.start().

                Subclasses can use this as a generic way to start
                a task.

                """
                task.addExitListener(exit_handler)
                self._current_task = task
                task.start()

class TaskSequence(CompositeTask):
        """
        A collection of tasks that executes sequentially. Each task
        must have a addExitListener() method that can be used as
        a means to trigger movement from one task to the next.
        """

        __slots__ = ("_task_queue",)

        def __init__(self, **kwargs):
                AsynchronousTask.__init__(self, **kwargs)
                self._task_queue = deque()

        def add(self, task):
                self._task_queue.append(task)

        def _start(self):
                self._start_next_task()

        def cancel(self):
                self._task_queue.clear()
                CompositeTask.cancel(self)

        def _start_next_task(self):
                self._start_task(self._task_queue.popleft(),
                        self._task_exit_handler)

        def _task_exit_handler(self, task):
                if self._default_exit(task) != os.EX_OK:
                        self.wait()
                elif self._task_queue:
                        self._start_next_task()
                else:
                        self._final_exit(task)
                        self.wait()

class SubProcess(AsynchronousTask):

        __slots__ = ("scheduler",) + ("pid", "_files", "_registered", "_reg_id")

        # A file descriptor is required for the scheduler to monitor changes from
        # inside a poll() loop. When logging is not enabled, create a pipe just to
        # serve this purpose alone.
        _dummy_pipe_fd = 9

        def _poll(self):
                if self.returncode is not None:
                        return self.returncode
                if self.pid is None:
                        return self.returncode
                if self._registered:
                        return self.returncode

                try:
                        retval = os.waitpid(self.pid, os.WNOHANG)
                except OSError, e:
                        if e.errno != errno.ECHILD:
                                raise
                        del e
                        retval = (self.pid, 1)

                if retval == (0, 0):
                        return None
                self._set_returncode(retval)
                return self.returncode

        def cancel(self):
                if self.isAlive():
                        try:
                                os.kill(self.pid, signal.SIGTERM)
                        except OSError, e:
                                if e.errno != errno.ESRCH:
                                        raise
                                del e

                self.cancelled = True
                if self.pid is not None:
                        self.wait()
                return self.returncode

        def isAlive(self):
                return self.pid is not None and \
                        self.returncode is None

        def _wait(self):

                if self.returncode is not None:
                        return self.returncode

                if self._registered:
                        self.scheduler.schedule(self._reg_id)
                        self._unregister()
                        if self.returncode is not None:
                                return self.returncode

                try:
                        wait_retval = os.waitpid(self.pid, 0)
                except OSError, e:
                        if e.errno != errno.ECHILD:
                                raise
                        del e
                        self._set_returncode((self.pid, 1))
                else:
                        self._set_returncode(wait_retval)

                return self.returncode

        def _unregister(self):
                """
                Unregister from the scheduler and close open files.
                """

                self._registered = False

                if self._reg_id is not None:
                        self.scheduler.unregister(self._reg_id)
                        self._reg_id = None

                if self._files is not None:
                        for f in self._files.itervalues():
                                f.close()
                        self._files = None

        def _set_returncode(self, wait_retval):

                retval = wait_retval[1]

                if retval != os.EX_OK:
                        if retval & 0xff:
                                retval = (retval & 0xff) << 8
                        else:
                                retval = retval >> 8

                self.returncode = retval

class SpawnProcess(SubProcess):

        """
        Constructor keyword args are passed into portage.process.spawn().
        The required "args" keyword argument will be passed as the first
        spawn() argument.
        """

        _spawn_kwarg_names = ("env", "opt_name", "fd_pipes",
                "uid", "gid", "groups", "umask", "logfile",
                "path_lookup", "pre_exec")

        __slots__ = ("args",) + \
                _spawn_kwarg_names

        _file_names = ("log", "process", "stdout")
        _files_dict = slot_dict_class(_file_names, prefix="")
        _bufsize = 4096

        def _start(self):

                if self.cancelled:
                        return

                if self.fd_pipes is None:
                        self.fd_pipes = {}
                fd_pipes = self.fd_pipes
                fd_pipes.setdefault(0, sys.stdin.fileno())
                fd_pipes.setdefault(1, sys.stdout.fileno())
                fd_pipes.setdefault(2, sys.stderr.fileno())

                # flush any pending output
                for fd in fd_pipes.itervalues():
                        if fd == sys.stdout.fileno():
                                sys.stdout.flush()
                        if fd == sys.stderr.fileno():
                                sys.stderr.flush()

                logfile = self.logfile
                self._files = self._files_dict()
                files = self._files

                master_fd, slave_fd = self._pipe(fd_pipes)
                fcntl.fcntl(master_fd, fcntl.F_SETFL,
                        fcntl.fcntl(master_fd, fcntl.F_GETFL) | os.O_NONBLOCK)

                null_input = None
                fd_pipes_orig = fd_pipes.copy()
                if self.background:
                        # TODO: Use job control functions like tcsetpgrp() to control
                        # access to stdin. Until then, use /dev/null so that any
                        # attempts to read from stdin will immediately return EOF
                        # instead of blocking indefinitely.
                        null_input = open('/dev/null', 'rb')
                        fd_pipes[0] = null_input.fileno()
                else:
                        fd_pipes[0] = fd_pipes_orig[0]

                files.process = os.fdopen(master_fd, 'r')
                if logfile is not None:

                        fd_pipes[1] = slave_fd
                        fd_pipes[2] = slave_fd

                        files.log = open(logfile, "a")
                        portage.util.apply_secpass_permissions(logfile,
                                uid=portage.portage_uid, gid=portage.portage_gid,
                                mode=0660)

                        if not self.background:
                                files.stdout = os.fdopen(os.dup(fd_pipes_orig[1]), 'w')

                        output_handler = self._output_handler

                else:

                        # Create a dummy pipe so the scheduler can monitor
                        # the process from inside a poll() loop.
                        fd_pipes[self._dummy_pipe_fd] = slave_fd
                        if self.background:
                                fd_pipes[1] = slave_fd
                                fd_pipes[2] = slave_fd
                        output_handler = self._dummy_handler

                kwargs = {}
                for k in self._spawn_kwarg_names:
                        v = getattr(self, k)
                        if v is not None:
                                kwargs[k] = v

                kwargs["fd_pipes"] = fd_pipes
                kwargs["returnpid"] = True
                kwargs.pop("logfile", None)

                retval = self._spawn(self.args, **kwargs)

                os.close(slave_fd)
                if null_input is not None:
                        null_input.close()

                if isinstance(retval, int):
                        # spawn failed
                        for f in files.values():
                                f.close()
                        self.returncode = retval
                        self.wait()
                        return

                self.pid = retval[0]
                portage.process.spawned_pids.remove(self.pid)

                self._reg_id = self.scheduler.register(files.process.fileno(),
                        PollConstants.POLLIN, output_handler)
                self._registered = True

        def _pipe(self, fd_pipes):
                """
                @type fd_pipes: dict
                @param fd_pipes: pipes from which to copy terminal size if desired.
                """
                return os.pipe()

        def _spawn(self, args, **kwargs):
                return portage.process.spawn(args, **kwargs)

        def _output_handler(self, fd, event):
                files = self._files
                buf = array.array('B')
                try:
                        buf.fromfile(files.process, self._bufsize)
                except EOFError:
                        pass
                if buf:
                        if not self.background:
                                buf.tofile(files.stdout)
                                files.stdout.flush()
                        buf.tofile(files.log)
                        files.log.flush()
                else:
                        self._unregister()
                        self.wait()
                return self._registered

        def _dummy_handler(self, fd, event):
                """
                This method is mainly interested in detecting EOF, since
                the only purpose of the pipe is to allow the scheduler to
                monitor the process from inside a poll() loop.
                """
                files = self._files
                buf = array.array('B')
                try:
                        buf.fromfile(files.process, self._bufsize)
                except EOFError:
                        pass
                if buf:
                        pass
                else:
                        self._unregister()
                        self.wait()
                return self._registered

class MiscFunctionsProcess(SpawnProcess):
        """
        Spawns misc-functions.sh with an existing ebuild environment.
        """

        __slots__ = ("commands", "phase", "pkg", "settings")

        def _start(self):
                settings = self.settings
                settings.pop("EBUILD_PHASE", None)
                portage_bin_path = settings["PORTAGE_BIN_PATH"]
                misc_sh_binary = os.path.join(portage_bin_path,
                        os.path.basename(portage.const.MISC_SH_BINARY))

                self.args = [portage._shell_quote(misc_sh_binary)] + self.commands
                self.logfile = settings.get("PORTAGE_LOG_FILE")

                portage._doebuild_exit_status_unlink(
                        settings.get("EBUILD_EXIT_STATUS_FILE"))

                SpawnProcess._start(self)

        def _spawn(self, args, **kwargs):
                settings = self.settings
                debug = settings.get("PORTAGE_DEBUG") == "1"
                return portage.spawn(" ".join(args), settings,
                        debug=debug, **kwargs)

        def _set_returncode(self, wait_retval):
                SpawnProcess._set_returncode(self, wait_retval)
                self.returncode = portage._doebuild_exit_status_check_and_log(
                        self.settings, self.phase, self.returncode)

class EbuildFetcher(SpawnProcess):

        __slots__ = ("config_pool", "fetchonly", "fetchall", "pkg", "prefetch") + \
                ("_build_dir",)

        def _start(self):

                root_config = self.pkg.root_config
                portdb = root_config.trees["porttree"].dbapi
                ebuild_path = portdb.findname(self.pkg.cpv)
                settings = self.config_pool.allocate()
                self._build_dir = EbuildBuildDir(pkg=self.pkg, settings=settings)
                self._build_dir.lock()
                self._build_dir.clean()
                portage.prepare_build_dirs(self.pkg.root, self._build_dir.settings, 0)
                if self.logfile is None:
                        self.logfile = settings.get("PORTAGE_LOG_FILE")

                phase = "fetch"
                if self.fetchall:
                        phase = "fetchall"

                # If any incremental variables have been overridden
                # via the environment, those values need to be passed
                # along here so that they are correctly considered by
                # the config instance in the subproccess.
                fetch_env = os.environ.copy()

                fetch_env["PORTAGE_NICENESS"] = "0"
                if self.prefetch:
                        fetch_env["PORTAGE_PARALLEL_FETCHONLY"] = "1"

                ebuild_binary = os.path.join(
                        settings["PORTAGE_BIN_PATH"], "ebuild")

                fetch_args = [ebuild_binary, ebuild_path, phase]
                debug = settings.get("PORTAGE_DEBUG") == "1"
                if debug:
                        fetch_args.append("--debug")

                self.args = fetch_args
                self.env = fetch_env
                SpawnProcess._start(self)

        def _pipe(self, fd_pipes):
                """When appropriate, use a pty so that fetcher progress bars,
                like wget has, will work properly."""
                if self.background or not sys.stdout.isatty():
                        # When the output only goes to a log file,
                        # there's no point in creating a pty.
                        return os.pipe()
                stdout_pipe = fd_pipes.get(1)
                got_pty, master_fd, slave_fd = \
                        portage._create_pty_or_pipe(copy_term_size=stdout_pipe)
                return (master_fd, slave_fd)

        def _set_returncode(self, wait_retval):
                SpawnProcess._set_returncode(self, wait_retval)
                # Collect elog messages that might have been
                # created by the pkg_nofetch phase.
                if self._build_dir is not None:
                        # Skip elog messages for prefetch, in order to avoid duplicates.
                        if not self.prefetch and self.returncode != os.EX_OK:
                                elog_out = None
                                if self.logfile is not None:
                                        if self.background:
                                                elog_out = open(self.logfile, 'a')
                                msg = "Fetch failed for '%s'" % (self.pkg.cpv,)
                                if self.logfile is not None:
                                        msg += ", Log file:"
                                eerror(msg, phase="unpack", key=self.pkg.cpv, out=elog_out)
                                if self.logfile is not None:
                                        eerror(" '%s'" % (self.logfile,),
                                                phase="unpack", key=self.pkg.cpv, out=elog_out)
                                if elog_out is not None:
                                        elog_out.close()
                        if not self.prefetch:
                                portage.elog.elog_process(self.pkg.cpv, self._build_dir.settings)
                        features = self._build_dir.settings.features
                        if self.returncode == os.EX_OK:
                                self._build_dir.clean()
                        self._build_dir.unlock()
                        self.config_pool.deallocate(self._build_dir.settings)
                        self._build_dir = None

class EbuildBuildDir(SlotObject):

        __slots__ = ("dir_path", "pkg", "settings",
                "locked", "_catdir", "_lock_obj")

        def __init__(self, **kwargs):
                SlotObject.__init__(self, **kwargs)
                self.locked = False

        def lock(self):
                """
                This raises an AlreadyLocked exception if lock() is called
                while a lock is already held. In order to avoid this, call
                unlock() or check whether the "locked" attribute is True
                or False before calling lock().
                """
                if self._lock_obj is not None:
                        raise self.AlreadyLocked((self._lock_obj,))

                dir_path = self.dir_path
                if dir_path is None:
                        root_config = self.pkg.root_config
                        portdb = root_config.trees["porttree"].dbapi
                        ebuild_path = portdb.findname(self.pkg.cpv)
                        settings = self.settings
                        settings.setcpv(self.pkg)
                        debug = settings.get("PORTAGE_DEBUG") == "1"
                        use_cache = 1 # always true
                        portage.doebuild_environment(ebuild_path, "setup", root_config.root,
                                self.settings, debug, use_cache, portdb)
                        dir_path = self.settings["PORTAGE_BUILDDIR"]

                catdir = os.path.dirname(dir_path)
                self._catdir = catdir

                portage.util.ensure_dirs(os.path.dirname(catdir),
                        gid=portage.portage_gid,
                        mode=070, mask=0)
                catdir_lock = None
                try:
                        catdir_lock = portage.locks.lockdir(catdir)
                        portage.util.ensure_dirs(catdir,
                                gid=portage.portage_gid,
                                mode=070, mask=0)
                        self._lock_obj = portage.locks.lockdir(dir_path)
                finally:
                        self.locked = self._lock_obj is not None
                        if catdir_lock is not None:
                                portage.locks.unlockdir(catdir_lock)

        def clean(self):
                """Uses shutil.rmtree() rather than spawning a 'clean' phase. Disabled
                by keepwork or keeptemp in FEATURES."""
                settings = self.settings
                features = settings.features
                if not ("keepwork" in features or "keeptemp" in features):
                        try:
                                shutil.rmtree(settings["PORTAGE_BUILDDIR"])
                        except EnvironmentError, e:
                                if e.errno != errno.ENOENT:
                                        raise
                                del e

        def unlock(self):
                if self._lock_obj is None:
                        return

                portage.locks.unlockdir(self._lock_obj)
                self._lock_obj = None
                self.locked = False

                catdir = self._catdir
                catdir_lock = None
                try:
                        catdir_lock = portage.locks.lockdir(catdir)
                finally:
                        if catdir_lock:
                                try:
                                        os.rmdir(catdir)
                                except OSError, e:
                                        if e.errno not in (errno.ENOENT,
                                                errno.ENOTEMPTY, errno.EEXIST):
                                                raise
                                        del e
                                portage.locks.unlockdir(catdir_lock)

        class AlreadyLocked(portage.exception.PortageException):
                pass

class EbuildBuild(CompositeTask):

        __slots__ = ("args_set", "config_pool", "find_blockers",
                "ldpath_mtimes", "logger", "opts", "pkg", "pkg_count",
                "prefetcher", "settings", "world_atom") + \
                ("_build_dir", "_buildpkg", "_ebuild_path", "_issyspkg", "_tree")

        def _start(self):

                logger = self.logger
                opts = self.opts
                pkg = self.pkg
                settings = self.settings
                world_atom = self.world_atom
                root_config = pkg.root_config
                tree = "porttree"
                self._tree = tree
                portdb = root_config.trees[tree].dbapi
                settings["EMERGE_FROM"] = pkg.type_name
                settings.backup_changes("EMERGE_FROM")
                settings.reset()
                ebuild_path = portdb.findname(self.pkg.cpv)
                self._ebuild_path = ebuild_path

                prefetcher = self.prefetcher
                if prefetcher is None:
                        pass
                elif not prefetcher.isAlive():
                        prefetcher.cancel()
                elif prefetcher.poll() is None:

                        waiting_msg = "Fetching files " + \
                                "in the background. " + \
                                "To view fetch progress, run `tail -f " + \
                                "/var/log/emerge-fetch.log` in another " + \
                                "terminal."
                        msg_prefix = colorize("GOOD", " * ")
                        from textwrap import wrap
                        waiting_msg = "".join("%s%s\n" % (msg_prefix, line) \
                                for line in wrap(waiting_msg, 65))
                        if not self.background:
                                writemsg(waiting_msg, noiselevel=-1)

                        self._current_task = prefetcher
                        prefetcher.addExitListener(self._prefetch_exit)
                        return

                self._prefetch_exit(prefetcher)

        def _prefetch_exit(self, prefetcher):

                opts = self.opts
                pkg = self.pkg
                settings = self.settings

                if opts.fetchonly:
                                fetcher = EbuildFetchonly(
                                        fetch_all=opts.fetch_all_uri,
                                        pkg=pkg, pretend=opts.pretend,
                                        settings=settings)
                                retval = fetcher.execute()
                                self.returncode = retval
                                self.wait()
                                return

                fetcher = EbuildFetcher(config_pool=self.config_pool,
                        fetchall=opts.fetch_all_uri,
                        fetchonly=opts.fetchonly,
                        background=self.background,
                        pkg=pkg, scheduler=self.scheduler)

                self._start_task(fetcher, self._fetch_exit)

        def _fetch_exit(self, fetcher):
                opts = self.opts
                pkg = self.pkg

                fetch_failed = False
                if opts.fetchonly:
                        fetch_failed = self._final_exit(fetcher) != os.EX_OK
                else:
                        fetch_failed = self._default_exit(fetcher) != os.EX_OK

                if fetch_failed and fetcher.logfile is not None and \
                        os.path.exists(fetcher.logfile):
                        self.settings["PORTAGE_LOG_FILE"] = fetcher.logfile

                if not fetch_failed and fetcher.logfile is not None:
                        # Fetch was successful, so remove the fetch log.
                        try:
                                os.unlink(fetcher.logfile)
                        except OSError:
                                pass

                if fetch_failed or opts.fetchonly:
                        self.wait()
                        return

                logger = self.logger
                opts = self.opts
                pkg_count = self.pkg_count
                scheduler = self.scheduler
                settings = self.settings
                features = settings.features
                ebuild_path = self._ebuild_path
                system_set = pkg.root_config.sets["system"]

                self._build_dir = EbuildBuildDir(pkg=pkg, settings=settings)
                self._build_dir.lock()

                # Cleaning is triggered before the setup
                # phase, in portage.doebuild().
                msg = " === (%s of %s) Cleaning (%s::%s)" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
                short_msg = "emerge: (%s of %s) %s Clean" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                logger.log(msg, short_msg=short_msg)

                #buildsyspkg: Check if we need to _force_ binary package creation
                self._issyspkg = "buildsyspkg" in features and \
                                system_set.findAtomForPackage(pkg) and \
                                not opts.buildpkg

                if opts.buildpkg or self._issyspkg:

                        self._buildpkg = True

                        msg = " === (%s of %s) Compiling/Packaging (%s::%s)" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
                        short_msg = "emerge: (%s of %s) %s Compile" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                        logger.log(msg, short_msg=short_msg)

                else:
                        msg = " === (%s of %s) Compiling/Merging (%s::%s)" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv, ebuild_path)
                        short_msg = "emerge: (%s of %s) %s Compile" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                        logger.log(msg, short_msg=short_msg)

                build = EbuildExecuter(background=self.background, pkg=pkg,
                        scheduler=scheduler, settings=settings)
                self._start_task(build, self._build_exit)

        def _unlock_builddir(self):
                portage.elog.elog_process(self.pkg.cpv, self.settings)
                self._build_dir.unlock()

        def _build_exit(self, build):
                if self._default_exit(build) != os.EX_OK:
                        self._unlock_builddir()
                        self.wait()
                        return

                opts = self.opts
                buildpkg = self._buildpkg

                if not buildpkg:
                        self._final_exit(build)
                        self.wait()
                        return

                if self._issyspkg:
                        msg = ">>> This is a system package, " + \
                                "let's pack a rescue tarball.\n"

                        log_path = self.settings.get("PORTAGE_LOG_FILE")
                        if log_path is not None:
                                log_file = open(log_path, 'a')
                                try:
                                        log_file.write(msg)
                                finally:
                                        log_file.close()

                        if not self.background:
                                portage.writemsg_stdout(msg, noiselevel=-1)

                packager = EbuildBinpkg(background=self.background, pkg=self.pkg,
                        scheduler=self.scheduler, settings=self.settings)

                self._start_task(packager, self._buildpkg_exit)

        def _buildpkg_exit(self, packager):
                """
                Released build dir lock when there is a failure or
                when in buildpkgonly mode. Otherwise, the lock will
                be released when merge() is called.
                """

                if self._default_exit(packager) == os.EX_OK and \
                        self.opts.buildpkgonly:
                        # Need to call "clean" phase for buildpkgonly mode
                        portage.elog.elog_process(self.pkg.cpv, self.settings)
                        phase = "clean"
                        clean_phase = EbuildPhase(background=self.background,
                                pkg=self.pkg, phase=phase,
                                scheduler=self.scheduler, settings=self.settings,
                                tree=self._tree)
                        self._start_task(clean_phase, self._clean_exit)
                        return

                if self._final_exit(packager) != os.EX_OK or \
                        self.opts.buildpkgonly:
                        self._unlock_builddir()
                self.wait()

        def _clean_exit(self, clean_phase):
                if self._final_exit(clean_phase) != os.EX_OK or \
                        self.opts.buildpkgonly:
                        self._unlock_builddir()
                self.wait()

        def install(self):
                """
                Install the package and then clean up and release locks.
                Only call this after the build has completed successfully
                and neither fetchonly nor buildpkgonly mode are enabled.
                """

                find_blockers = self.find_blockers
                ldpath_mtimes = self.ldpath_mtimes
                logger = self.logger
                pkg = self.pkg
                pkg_count = self.pkg_count
                settings = self.settings
                world_atom = self.world_atom
                ebuild_path = self._ebuild_path
                tree = self._tree

                merge = EbuildMerge(find_blockers=self.find_blockers,
                        ldpath_mtimes=ldpath_mtimes, logger=logger, pkg=pkg,
                        pkg_count=pkg_count, pkg_path=ebuild_path,
                        scheduler=self.scheduler,
                        settings=settings, tree=tree, world_atom=world_atom)

                msg = " === (%s of %s) Merging (%s::%s)" % \
                        (pkg_count.curval, pkg_count.maxval,
                        pkg.cpv, ebuild_path)
                short_msg = "emerge: (%s of %s) %s Merge" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                logger.log(msg, short_msg=short_msg)

                try:
                        rval = merge.execute()
                finally:
                        self._unlock_builddir()

                return rval

class EbuildExecuter(CompositeTask):

        __slots__ = ("pkg", "scheduler", "settings") + ("_tree",)

        _phases = ("prepare", "configure", "compile", "test", "install")

        _live_eclasses = frozenset([
                "bzr",
                "cvs",
                "darcs",
                "git",
                "mercurial",
                "subversion"
        ])

        def _start(self):
                self._tree = "porttree"
                pkg = self.pkg
                phase = "clean"
                clean_phase = EbuildPhase(background=self.background, pkg=pkg, phase=phase,
                        scheduler=self.scheduler, settings=self.settings, tree=self._tree)
                self._start_task(clean_phase, self._clean_phase_exit)

        def _clean_phase_exit(self, clean_phase):

                if self._default_exit(clean_phase) != os.EX_OK:
                        self.wait()
                        return

                pkg = self.pkg
                scheduler = self.scheduler
                settings = self.settings
                cleanup = 1

                # This initializes PORTAGE_LOG_FILE.
                portage.prepare_build_dirs(pkg.root, settings, cleanup)

                setup_phase = EbuildPhase(background=self.background,
                        pkg=pkg, phase="setup", scheduler=scheduler,
                        settings=settings, tree=self._tree)

                setup_phase.addExitListener(self._setup_exit)
                self._current_task = setup_phase
                self.scheduler.scheduleSetup(setup_phase)

        def _setup_exit(self, setup_phase):

                if self._default_exit(setup_phase) != os.EX_OK:
                        self.wait()
                        return

                unpack_phase = EbuildPhase(background=self.background,
                        pkg=self.pkg, phase="unpack", scheduler=self.scheduler,
                        settings=self.settings, tree=self._tree)

                if self._live_eclasses.intersection(self.pkg.inherited):
                        # Serialize $DISTDIR access for live ebuilds since
                        # otherwise they can interfere with eachother.

                        unpack_phase.addExitListener(self._unpack_exit)
                        self._current_task = unpack_phase
                        self.scheduler.scheduleUnpack(unpack_phase)

                else:
                        self._start_task(unpack_phase, self._unpack_exit)

        def _unpack_exit(self, unpack_phase):

                if self._default_exit(unpack_phase) != os.EX_OK:
                        self.wait()
                        return

                ebuild_phases = TaskSequence(scheduler=self.scheduler)

                pkg = self.pkg
                phases = self._phases
                eapi = pkg.metadata["EAPI"]
                if eapi in ("0", "1", "2_pre1"):
                        # skip src_prepare and src_configure
                        phases = phases[2:]
                elif eapi in ("2_pre2",):
                        # skip src_prepare
                        phases = phases[1:]

                for phase in phases:
                        ebuild_phases.add(EbuildPhase(background=self.background,
                                pkg=self.pkg, phase=phase, scheduler=self.scheduler,
                                settings=self.settings, tree=self._tree))

                self._start_task(ebuild_phases, self._default_final_exit)

class EbuildMetadataPhase(SubProcess):

        """
        Asynchronous interface for the ebuild "depend" phase which is
        used to extract metadata from the ebuild.
        """

        __slots__ = ("cpv", "ebuild_path", "fd_pipes", "metadata_callback",
                "ebuild_mtime", "portdb", "repo_path", "settings") + \
                ("_raw_metadata",)

        _file_names = ("ebuild",)
        _files_dict = slot_dict_class(_file_names, prefix="")
        _bufsize = SpawnProcess._bufsize
        _metadata_fd = 9

        def _start(self):
                settings = self.settings
                settings.reset()
                ebuild_path = self.ebuild_path
                debug = settings.get("PORTAGE_DEBUG") == "1"
                master_fd = None
                slave_fd = None
                fd_pipes = None
                if self.fd_pipes is not None:
                        fd_pipes = self.fd_pipes.copy()
                else:
                        fd_pipes = {}

                fd_pipes.setdefault(0, sys.stdin.fileno())
                fd_pipes.setdefault(1, sys.stdout.fileno())
                fd_pipes.setdefault(2, sys.stderr.fileno())

                # flush any pending output
                for fd in fd_pipes.itervalues():
                        if fd == sys.stdout.fileno():
                                sys.stdout.flush()
                        if fd == sys.stderr.fileno():
                                sys.stderr.flush()

                fd_pipes_orig = fd_pipes.copy()
                self._files = self._files_dict()
                files = self._files

                master_fd, slave_fd = os.pipe()
                fcntl.fcntl(master_fd, fcntl.F_SETFL,
                        fcntl.fcntl(master_fd, fcntl.F_GETFL) | os.O_NONBLOCK)

                fd_pipes[self._metadata_fd] = slave_fd

                retval = portage.doebuild(ebuild_path, "depend",
                        settings["ROOT"], settings, debug,
                        mydbapi=self.portdb, tree="porttree",
                        fd_pipes=fd_pipes, returnpid=True)

                os.close(slave_fd)

                if isinstance(retval, int):
                        # doebuild failed before spawning
                        os.close(master_fd)
                        self.returncode = retval
                        self.wait()
                        return

                self.pid = retval[0]
                portage.process.spawned_pids.remove(self.pid)

                self._raw_metadata = []
                files.ebuild = os.fdopen(master_fd, 'r')
                self._reg_id = self.scheduler.register(files.ebuild.fileno(),
                        PollConstants.POLLIN, self._output_handler)
                self._registered = True

        def _output_handler(self, fd, event):
                files = self._files
                self._raw_metadata.append(files.ebuild.read())
                if not self._raw_metadata[-1]:
                        self._unregister()
                        self.wait()

                        if self.returncode == os.EX_OK:
                                metadata = izip(portage.auxdbkeys,
                                        "".join(self._raw_metadata).splitlines())
                                self.metadata_callback(self.cpv, self.ebuild_path,
                                        self.repo_path, metadata, self.ebuild_mtime)

                return self._registered

class EbuildProcess(SpawnProcess):

        __slots__ = ("phase", "pkg", "settings", "tree")

        def _start(self):
                # Don't open the log file during the clean phase since the
                # open file can result in an nfs lock on $T/build.log which
                # prevents the clean phase from removing $T.
                if self.phase not in ("clean", "cleanrm"):
                        self.logfile = self.settings.get("PORTAGE_LOG_FILE")
                SpawnProcess._start(self)

        def _pipe(self, fd_pipes):
                stdout_pipe = fd_pipes.get(1)
                got_pty, master_fd, slave_fd = \
                        portage._create_pty_or_pipe(copy_term_size=stdout_pipe)
                return (master_fd, slave_fd)

        def _spawn(self, args, **kwargs):

                root_config = self.pkg.root_config
                tree = self.tree
                mydbapi = root_config.trees[tree].dbapi
                settings = self.settings
                ebuild_path = settings["EBUILD"]
                debug = settings.get("PORTAGE_DEBUG") == "1"

                rval = portage.doebuild(ebuild_path, self.phase,
                        root_config.root, settings, debug,
                        mydbapi=mydbapi, tree=tree, **kwargs)

                return rval

        def _set_returncode(self, wait_retval):
                SpawnProcess._set_returncode(self, wait_retval)

                if self.phase not in ("clean", "cleanrm"):
                        self.returncode = portage._doebuild_exit_status_check_and_log(
                                self.settings, self.phase, self.returncode)

                portage._post_phase_userpriv_perms(self.settings)

class EbuildPhase(CompositeTask):

        __slots__ = ("background", "pkg", "phase",
                "scheduler", "settings", "tree")

        _post_phase_cmds = portage._post_phase_cmds

        def _start(self):

                ebuild_process = EbuildProcess(background=self.background,
                        pkg=self.pkg, phase=self.phase, scheduler=self.scheduler,
                        settings=self.settings, tree=self.tree)

                self._start_task(ebuild_process, self._ebuild_exit)

        def _ebuild_exit(self, ebuild_process):

                if self.phase == "install":
                        out = None
                        log_path = self.settings.get("PORTAGE_LOG_FILE")
                        log_file = None
                        if self.background and log_path is not None:
                                log_file = open(log_path, 'a')
                                out = log_file
                        try:
                                portage._check_build_log(self.settings, out=out)
                        finally:
                                if log_file is not None:
                                        log_file.close()

                if self._default_exit(ebuild_process) != os.EX_OK:
                        self.wait()
                        return

                settings = self.settings

                if self.phase == "install":
                        portage._post_src_install_uid_fix(settings)

                post_phase_cmds = self._post_phase_cmds.get(self.phase)
                if post_phase_cmds is not None:
                        post_phase = MiscFunctionsProcess(background=self.background,
                                commands=post_phase_cmds, phase=self.phase, pkg=self.pkg,
                                scheduler=self.scheduler, settings=settings)
                        self._start_task(post_phase, self._post_phase_exit)
                        return

                self.returncode = ebuild_process.returncode
                self._current_task = None
                self.wait()

        def _post_phase_exit(self, post_phase):
                if self._final_exit(post_phase) != os.EX_OK:
                        writemsg("!!! post %s failed; exiting.\n" % self.phase,
                                noiselevel=-1)
                self._current_task = None
                self.wait()
                return

class EbuildBinpkg(EbuildProcess):
        """
        This assumes that src_install() has successfully completed.
        """
        __slots__ = ("_binpkg_tmpfile",)

        def _start(self):
                self.phase = "package"
                self.tree = "porttree"
                pkg = self.pkg
                root_config = pkg.root_config
                portdb = root_config.trees["porttree"].dbapi
                bintree = root_config.trees["bintree"]
                ebuild_path = portdb.findname(self.pkg.cpv)
                settings = self.settings
                debug = settings.get("PORTAGE_DEBUG") == "1"

                bintree.prevent_collision(pkg.cpv)
                binpkg_tmpfile = os.path.join(bintree.pkgdir,
                        pkg.cpv + ".tbz2." + str(os.getpid()))
                self._binpkg_tmpfile = binpkg_tmpfile
                settings["PORTAGE_BINPKG_TMPFILE"] = binpkg_tmpfile
                settings.backup_changes("PORTAGE_BINPKG_TMPFILE")

                try:
                        EbuildProcess._start(self)
                finally:
                        settings.pop("PORTAGE_BINPKG_TMPFILE", None)

        def _set_returncode(self, wait_retval):
                EbuildProcess._set_returncode(self, wait_retval)

                pkg = self.pkg
                bintree = pkg.root_config.trees["bintree"]
                binpkg_tmpfile = self._binpkg_tmpfile
                if self.returncode == os.EX_OK:
                        bintree.inject(pkg.cpv, filename=binpkg_tmpfile)

class EbuildMerge(SlotObject):

        __slots__ = ("find_blockers", "logger", "ldpath_mtimes",
                "pkg", "pkg_count", "pkg_path", "pretend",
                "scheduler", "settings", "tree", "world_atom")

        def execute(self):
                root_config = self.pkg.root_config
                settings = self.settings
                retval = portage.merge(settings["CATEGORY"],
                        settings["PF"], settings["D"],
                        os.path.join(settings["PORTAGE_BUILDDIR"],
                        "build-info"), root_config.root, settings,
                        myebuild=settings["EBUILD"],
                        mytree=self.tree, mydbapi=root_config.trees[self.tree].dbapi,
                        vartree=root_config.trees["vartree"],
                        prev_mtimes=self.ldpath_mtimes,
                        scheduler=self.scheduler,
                        blockers=self.find_blockers)

                if retval == os.EX_OK:
                        self.world_atom(self.pkg)
                        self._log_success()

                return retval

        def _log_success(self):
                pkg = self.pkg
                pkg_count = self.pkg_count
                pkg_path = self.pkg_path
                logger = self.logger
                if "noclean" not in self.settings.features:
                        short_msg = "emerge: (%s of %s) %s Clean Post" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                        logger.log((" === (%s of %s) " + \
                                "Post-Build Cleaning (%s::%s)") % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg_path),
                                short_msg=short_msg)
                logger.log(" ::: completed emerge (%s of %s) %s to %s" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg.root))

class PackageUninstall(AsynchronousTask):

        __slots__ = ("ldpath_mtimes", "opts", "pkg", "scheduler", "settings")

        def _start(self):
                try:
                        unmerge(self.pkg.root_config, self.opts, "unmerge",
                                [self.pkg.cpv], self.ldpath_mtimes, clean_world=0,
                                clean_delay=0, raise_on_error=1, scheduler=self.scheduler,
                                writemsg_level=self._writemsg_level)
                except UninstallFailure, e:
                        self.returncode = e.status
                else:
                        self.returncode = os.EX_OK
                self.wait()

        def _writemsg_level(self, msg, level=0, noiselevel=0):

                log_path = self.settings.get("PORTAGE_LOG_FILE")
                background = self.background

                if log_path is None:
                        if not (background and level < logging.WARNING):
                                portage.util.writemsg_level(msg,
                                        level=level, noiselevel=noiselevel)
                else:
                        if not background:
                                portage.util.writemsg_level(msg,
                                        level=level, noiselevel=noiselevel)

                        f = open(log_path, 'a')
                        try:
                                f.write(msg)
                        finally:
                                f.close()

class Binpkg(CompositeTask):

        __slots__ = ("find_blockers",
                "ldpath_mtimes", "logger", "opts",
                "pkg", "pkg_count", "prefetcher", "settings", "world_atom") + \
                ("_bintree", "_build_dir", "_ebuild_path", "_fetched_pkg",
                "_image_dir", "_infloc", "_pkg_path", "_tree", "_verify")

        def _writemsg_level(self, msg, level=0, noiselevel=0):

                if not self.background:
                        portage.util.writemsg_level(msg,
                                level=level, noiselevel=noiselevel)

                log_path = self.settings.get("PORTAGE_LOG_FILE")
                if  log_path is not None:
                        f = open(log_path, 'a')
                        try:
                                f.write(msg)
                        finally:
                                f.close()

        def _start(self):

                pkg = self.pkg
                settings = self.settings
                settings.setcpv(pkg)
                self._tree = "bintree"
                self._bintree = self.pkg.root_config.trees[self._tree]
                self._verify = "strict" in self.settings.features and \
                        not self.opts.pretend

                dir_path = os.path.join(settings["PORTAGE_TMPDIR"],
                        "portage", pkg.category, pkg.pf)
                self._build_dir = EbuildBuildDir(dir_path=dir_path,
                        pkg=pkg, settings=settings)
                self._image_dir = os.path.join(dir_path, "image")
                self._infloc = os.path.join(dir_path, "build-info")
                self._ebuild_path = os.path.join(self._infloc, pkg.pf + ".ebuild")

                # The prefetcher has already completed or it
                # could be running now. If it's running now,
                # wait for it to complete since it holds
                # a lock on the file being fetched. The
                # portage.locks functions are only designed
                # to work between separate processes. Since
                # the lock is held by the current process,
                # use the scheduler and fetcher methods to
                # synchronize with the fetcher.
                prefetcher = self.prefetcher
                if prefetcher is None:
                        pass
                elif not prefetcher.isAlive():
                        prefetcher.cancel()
                elif prefetcher.poll() is None:

                        waiting_msg = ("Fetching '%s' " + \
                                "in the background. " + \
                                "To view fetch progress, run `tail -f " + \
                                "/var/log/emerge-fetch.log` in another " + \
                                "terminal.") % prefetcher.pkg_path
                        msg_prefix = colorize("GOOD", " * ")
                        from textwrap import wrap
                        waiting_msg = "".join("%s%s\n" % (msg_prefix, line) \
                                for line in wrap(waiting_msg, 65))
                        if not self.background:
                                writemsg(waiting_msg, noiselevel=-1)

                        self._current_task = prefetcher
                        prefetcher.addExitListener(self._prefetch_exit)
                        return

                self._prefetch_exit(prefetcher)

        def _prefetch_exit(self, prefetcher):

                pkg = self.pkg
                pkg_count = self.pkg_count
                fetcher = BinpkgFetcher(background=self.background,
                        logfile=self.scheduler.fetch.log_file, pkg=self.pkg,
                        scheduler=self.scheduler)
                pkg_path = fetcher.pkg_path
                self._pkg_path = pkg_path

                if self.opts.getbinpkg and self._bintree.isremote(pkg.cpv):

                        msg = " --- (%s of %s) Fetching Binary (%s::%s)" %\
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg_path)
                        short_msg = "emerge: (%s of %s) %s Fetch" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                        self.logger.log(msg, short_msg=short_msg)

                        if self.background:
                                fetcher.addExitListener(self._fetcher_exit)
                                self._current_task = fetcher
                                self.scheduler.fetch.schedule(fetcher)
                        else:
                                self._start_task(fetcher, self._fetcher_exit)
                        return

                self._fetcher_exit(fetcher)

        def _fetcher_exit(self, fetcher):

                # The fetcher only has a returncode when
                # --getbinpkg is enabled.
                if fetcher.returncode is not None:
                        self._fetched_pkg = True
                        if self.opts.fetchonly:
                                self._final_exit(fetcher)
                                self.wait()
                                return
                        elif self._default_exit(fetcher) != os.EX_OK:
                                self.wait()
                                return

                verifier = None
                if self._verify:
                        verifier = BinpkgVerifier(background=self.background,
                                logfile=self.scheduler.fetch.log_file, pkg=self.pkg)

                        if self.background:
                                verifier.addExitListener(self._verifier_exit)
                                self._current_task = verifier
                                self.scheduler.fetch.schedule(verifier)
                        else:
                                self._start_task(verifier, self._verifier_exit)
                        return

                self._verifier_exit(verifier)

        def _verifier_exit(self, verifier):
                if verifier is not None and \
                        self._default_exit(verifier) != os.EX_OK:
                        self.wait()
                        return

                logger = self.logger
                pkg = self.pkg
                pkg_count = self.pkg_count
                pkg_path = self._pkg_path

                if self._fetched_pkg:
                        self._bintree.inject(pkg.cpv, filename=pkg_path)

                msg = " === (%s of %s) Merging Binary (%s::%s)" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg_path)
                short_msg = "emerge: (%s of %s) %s Merge Binary" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv)
                logger.log(msg, short_msg=short_msg)

                self._build_dir.lock()

                phase = "clean"
                settings = self.settings
                settings.setcpv(pkg)
                settings["EBUILD"] = self._ebuild_path
                ebuild_phase = EbuildPhase(background=self.background,
                        pkg=pkg, phase=phase, scheduler=self.scheduler,
                        settings=settings, tree=self._tree)

                self._start_task(ebuild_phase, self._clean_exit)

        def _clean_exit(self, clean_phase):
                if self._default_exit(clean_phase) != os.EX_OK:
                        self._unlock_builddir()
                        self.wait()
                        return

                dir_path = self._build_dir.dir_path

                try:
                        shutil.rmtree(dir_path)
                except (IOError, OSError), e:
                        if e.errno != errno.ENOENT:
                                raise
                        del e

                infloc = self._infloc
                pkg = self.pkg
                pkg_path = self._pkg_path

                dir_mode = 0755
                for mydir in (dir_path, self._image_dir, infloc):
                        portage.util.ensure_dirs(mydir, uid=portage.data.portage_uid,
                                gid=portage.data.portage_gid, mode=dir_mode)

                # This initializes PORTAGE_LOG_FILE.
                portage.prepare_build_dirs(self.settings["ROOT"], self.settings, 1)
                self._writemsg_level(">>> Extracting info\n")

                pkg_xpak = portage.xpak.tbz2(self._pkg_path)
                check_missing_metadata = ("CATEGORY", "PF")
                missing_metadata = set()
                for k in check_missing_metadata:
                        v = pkg_xpak.getfile(k)
                        if not v:
                                missing_metadata.add(k)

                pkg_xpak.unpackinfo(infloc)
                for k in missing_metadata:
                        if k == "CATEGORY":
                                v = pkg.category
                        elif k == "PF":
                                v = pkg.pf
                        else:
                                continue

                        f = open(os.path.join(infloc, k), 'wb')
                        try:
                                f.write(v + "\n")
                        finally:
                                f.close()

                # Store the md5sum in the vdb.
                f = open(os.path.join(infloc, "BINPKGMD5"), "w")
                try:
                        f.write(str(portage.checksum.perform_md5(pkg_path)) + "\n")
                finally:
                        f.close()

                # This gives bashrc users an opportunity to do various things
                # such as remove binary packages after they're installed.
                settings = self.settings
                settings.setcpv(self.pkg)
                settings["PORTAGE_BINPKG_FILE"] = pkg_path
                settings.backup_changes("PORTAGE_BINPKG_FILE")

                phase = "setup"
                setup_phase = EbuildPhase(background=self.background,
                        pkg=self.pkg, phase=phase, scheduler=self.scheduler,
                        settings=settings, tree=self._tree)

                setup_phase.addExitListener(self._setup_exit)
                self._current_task = setup_phase
                self.scheduler.scheduleSetup(setup_phase)

        def _setup_exit(self, setup_phase):
                if self._default_exit(setup_phase) != os.EX_OK:
                        self._unlock_builddir()
                        self.wait()
                        return

                extractor = BinpkgExtractorAsync(background=self.background,
                        image_dir=self._image_dir,
                        pkg=self.pkg, pkg_path=self._pkg_path, scheduler=self.scheduler)
                self._writemsg_level(">>> Extracting %s\n" % self.pkg.cpv)
                self._start_task(extractor, self._extractor_exit)

        def _extractor_exit(self, extractor):
                if self._final_exit(extractor) != os.EX_OK:
                        self._unlock_builddir()
                        writemsg("!!! Error Extracting '%s'\n" % self._pkg_path,
                                noiselevel=-1)
                self.wait()

        def _unlock_builddir(self):
                portage.elog.elog_process(self.pkg.cpv, self.settings)
                self._build_dir.unlock()

        def install(self):

                # This gives bashrc users an opportunity to do various things
                # such as remove binary packages after they're installed.
                settings = self.settings
                settings["PORTAGE_BINPKG_FILE"] = self._pkg_path
                settings.backup_changes("PORTAGE_BINPKG_FILE")

                merge = EbuildMerge(find_blockers=self.find_blockers,
                        ldpath_mtimes=self.ldpath_mtimes, logger=self.logger,
                        pkg=self.pkg, pkg_count=self.pkg_count,
                        pkg_path=self._pkg_path, scheduler=self.scheduler,
                        settings=settings, tree=self._tree, world_atom=self.world_atom)

                try:
                        retval = merge.execute()
                finally:
                        settings.pop("PORTAGE_BINPKG_FILE", None)
                        self._unlock_builddir()
                return retval

class BinpkgFetcher(SpawnProcess):

        __slots__ = ("pkg",
                "locked", "pkg_path", "_lock_obj")

        def __init__(self, **kwargs):
                SpawnProcess.__init__(self, **kwargs)
                pkg = self.pkg
                self.pkg_path = pkg.root_config.trees["bintree"].getname(pkg.cpv)

        def _start(self):

                if self.cancelled:
                        return

                pkg = self.pkg
                bintree = pkg.root_config.trees["bintree"]
                settings = bintree.settings
                use_locks = "distlocks" in settings.features
                pkg_path = self.pkg_path
                resume = os.path.exists(pkg_path)

                # urljoin doesn't work correctly with
                # unrecognized protocols like sftp
                if bintree._remote_has_index:
                        rel_uri = bintree._remotepkgs[pkg.cpv].get("PATH")
                        if not rel_uri:
                                rel_uri = pkg.cpv + ".tbz2"
                        uri = bintree._remote_base_uri.rstrip("/") + \
                                "/" + rel_uri.lstrip("/")
                else:
                        uri = settings["PORTAGE_BINHOST"].rstrip("/") + \
                                "/" + pkg.pf + ".tbz2"

                protocol = urlparse.urlparse(uri)[0]
                fcmd_prefix = "FETCHCOMMAND"
                if resume:
                        fcmd_prefix = "RESUMECOMMAND"
                fcmd = settings.get(fcmd_prefix + "_" + protocol.upper())
                if not fcmd:
                        fcmd = settings.get(fcmd_prefix)

                fcmd_vars = {
                        "DISTDIR" : os.path.dirname(pkg_path),
                        "URI"     : uri,
                        "FILE"    : os.path.basename(pkg_path)
                }

                fetch_env = dict(settings.iteritems())
                fetch_args = [portage.util.varexpand(x, mydict=fcmd_vars) \
                        for x in shlex.split(fcmd)]

                portage.util.ensure_dirs(os.path.dirname(pkg_path))
                if use_locks:
                        self.lock()

                if self.fd_pipes is None:
                        self.fd_pipes = {}
                fd_pipes = self.fd_pipes

                # Redirect all output to stdout since some fetchers like
                # wget pollute stderr (if portage detects a problem then it
                # can send it's own message to stderr).
                fd_pipes.setdefault(0, sys.stdin.fileno())
                fd_pipes.setdefault(1, sys.stdout.fileno())
                fd_pipes.setdefault(2, sys.stdout.fileno())

                self.args = fetch_args
                self.env = fetch_env
                SpawnProcess._start(self)

        def _set_returncode(self, wait_retval):
                SpawnProcess._set_returncode(self, wait_retval)
                if self.locked:
                        self.unlock()

        def lock(self):
                """
                This raises an AlreadyLocked exception if lock() is called
                while a lock is already held. In order to avoid this, call
                unlock() or check whether the "locked" attribute is True
                or False before calling lock().
                """
                if self._lock_obj is not None:
                        raise self.AlreadyLocked((self._lock_obj,))

                self._lock_obj = portage.locks.lockfile(
                        self.pkg_path, wantnewlockfile=1)
                self.locked = True

        class AlreadyLocked(portage.exception.PortageException):
                pass

        def unlock(self):
                if self._lock_obj is None:
                        return
                portage.locks.unlockfile(self._lock_obj)
                self._lock_obj = None
                self.locked = False

class BinpkgVerifier(AsynchronousTask):
        __slots__ = ("logfile", "pkg",)

        def _start(self):
                """
                Note: Unlike a normal AsynchronousTask.start() method,
                this one does all work is synchronously. The returncode
                attribute will be set before it returns.
                """

                pkg = self.pkg
                root_config = pkg.root_config
                bintree = root_config.trees["bintree"]
                rval = os.EX_OK
                stdout_orig = sys.stdout
                stderr_orig = sys.stderr
                log_file = None
                if self.background and self.logfile is not None:
                        log_file = open(self.logfile, 'a')
                try:
                        if log_file is not None:
                                sys.stdout = log_file
                                sys.stderr = log_file
                        try:
                                bintree.digestCheck(pkg)
                        except portage.exception.FileNotFound:
                                writemsg("!!! Fetching Binary failed " + \
                                        "for '%s'\n" % pkg.cpv, noiselevel=-1)
                                rval = 1
                        except portage.exception.DigestException, e:
                                writemsg("\n!!! Digest verification failed:\n",
                                        noiselevel=-1)
                                writemsg("!!! %s\n" % e.value[0],
                                        noiselevel=-1)
                                writemsg("!!! Reason: %s\n" % e.value[1],
                                        noiselevel=-1)
                                writemsg("!!! Got: %s\n" % e.value[2],
                                        noiselevel=-1)
                                writemsg("!!! Expected: %s\n" % e.value[3],
                                        noiselevel=-1)
                                rval = 1
                finally:
                        sys.stdout = stdout_orig
                        sys.stderr = stderr_orig
                        if log_file is not None:
                                log_file.close()

                self.returncode = rval
                self.wait()

class BinpkgExtractorAsync(SpawnProcess):

        __slots__ = ("image_dir", "pkg", "pkg_path")

        _shell_binary = portage.const.BASH_BINARY

        def _start(self):
                self.args = [self._shell_binary, "-c",
                        "bzip2 -dqc -- %s | tar -xp -C %s -f -" % \
                        (portage._shell_quote(self.pkg_path),
                        portage._shell_quote(self.image_dir))]

                self.env = self.pkg.root_config.settings.environ()
                SpawnProcess._start(self)

class MergeListItem(CompositeTask):

        """
        TODO: For parallel scheduling, everything here needs asynchronous
        execution support (start, poll, and wait methods).
        """

        __slots__ = ("args_set",
                "binpkg_opts", "build_opts", "config_pool", "emerge_opts",
                "find_blockers", "logger", "mtimedb", "pkg",
                "pkg_count", "pkg_to_replace", "prefetcher",
                "settings", "statusMessage", "world_atom") + \
                ("_install_task",)

        def _start(self):

                pkg = self.pkg
                build_opts = self.build_opts

                if pkg.installed:
                        # uninstall,  executed by self.merge()
                        self.returncode = os.EX_OK
                        self.wait()
                        return

                args_set = self.args_set
                find_blockers = self.find_blockers
                logger = self.logger
                mtimedb = self.mtimedb
                pkg_count = self.pkg_count
                scheduler = self.scheduler
                settings = self.settings
                world_atom = self.world_atom
                ldpath_mtimes = mtimedb["ldpath"]

                action_desc = "Emerging"
                preposition = "for"
                if pkg.type_name == "binary":
                        action_desc += " binary"

                if build_opts.fetchonly:
                        action_desc = "Fetching"

                msg = "%s (%s of %s) %s" % \
                        (action_desc,
                        colorize("MERGE_LIST_PROGRESS", str(pkg_count.curval)),
                        colorize("MERGE_LIST_PROGRESS", str(pkg_count.maxval)),
                        colorize("GOOD", pkg.cpv))

                if pkg.root != "/":
                        msg += " %s %s" % (preposition, pkg.root)

                if not build_opts.pretend:
                        self.statusMessage(msg)
                        logger.log(" >>> emerge (%s of %s) %s to %s" % \
                                (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg.root))

                if pkg.type_name == "ebuild":

                        build = EbuildBuild(args_set=args_set,
                                background=self.background,
                                config_pool=self.config_pool,
                                find_blockers=find_blockers,
                                ldpath_mtimes=ldpath_mtimes, logger=logger,
                                opts=build_opts, pkg=pkg, pkg_count=pkg_count,
                                prefetcher=self.prefetcher, scheduler=scheduler,
                                settings=settings, world_atom=world_atom)

                        self._install_task = build
                        self._start_task(build, self._default_final_exit)
                        return

                elif pkg.type_name == "binary":

                        binpkg = Binpkg(background=self.background,
                                find_blockers=find_blockers,
                                ldpath_mtimes=ldpath_mtimes, logger=logger,
                                opts=self.binpkg_opts, pkg=pkg, pkg_count=pkg_count,
                                prefetcher=self.prefetcher, settings=settings,
                                scheduler=scheduler, world_atom=world_atom)

                        self._install_task = binpkg
                        self._start_task(binpkg, self._default_final_exit)
                        return

        def _poll(self):
                self._install_task.poll()
                return self.returncode

        def _wait(self):
                self._install_task.wait()
                return self.returncode

        def merge(self):

                pkg = self.pkg
                build_opts = self.build_opts
                find_blockers = self.find_blockers
                logger = self.logger
                mtimedb = self.mtimedb
                pkg_count = self.pkg_count
                prefetcher = self.prefetcher
                scheduler = self.scheduler
                settings = self.settings
                world_atom = self.world_atom
                ldpath_mtimes = mtimedb["ldpath"]

                if pkg.installed:
                        if not (build_opts.buildpkgonly or \
                                build_opts.fetchonly or build_opts.pretend):

                                uninstall = PackageUninstall(background=self.background,
                                        ldpath_mtimes=ldpath_mtimes, opts=self.emerge_opts,
                                        pkg=pkg, scheduler=scheduler, settings=settings)

                                uninstall.start()
                                retval = uninstall.wait()
                                if retval != os.EX_OK:
                                        return retval
                        return os.EX_OK

                if build_opts.fetchonly or \
                        build_opts.buildpkgonly:
                        return self.returncode

                retval = self._install_task.install()
                return retval

class PackageMerge(AsynchronousTask):
        """
        TODO: Implement asynchronous merge so that the scheduler can
        run while a merge is executing.
        """

        __slots__ = ("merge",)

        def _start(self):

                pkg = self.merge.pkg
                pkg_count = self.merge.pkg_count

                if pkg.installed:
                        action_desc = "Uninstalling"
                        preposition = "from"
                else:
                        action_desc = "Installing"
                        preposition = "to"

                msg = "%s %s" % (action_desc, colorize("GOOD", pkg.cpv))

                if pkg.root != "/":
                        msg += " %s %s" % (preposition, pkg.root)

                if not self.merge.build_opts.fetchonly and \
                        not self.merge.build_opts.pretend and \
                        not self.merge.build_opts.buildpkgonly:
                        self.merge.statusMessage(msg)

                self.returncode = self.merge.merge()
                self.wait()

class DependencyArg(object):
        def __init__(self, arg=None, root_config=None):
                self.arg = arg
                self.root_config = root_config

        def __str__(self):
                return self.arg

class AtomArg(DependencyArg):
        def __init__(self, atom=None, **kwargs):
                DependencyArg.__init__(self, **kwargs)
                self.atom = atom
                if not isinstance(self.atom, portage.dep.Atom):
                        self.atom = portage.dep.Atom(self.atom)
                self.set = (self.atom, )

class PackageArg(DependencyArg):
        def __init__(self, package=None, **kwargs):
                DependencyArg.__init__(self, **kwargs)
                self.package = package
                self.atom = portage.dep.Atom("=" + package.cpv)
                self.set = (self.atom, )

class SetArg(DependencyArg):
        def __init__(self, set=None, **kwargs):
                DependencyArg.__init__(self, **kwargs)
                self.set = set
                self.name = self.arg[len(SETPREFIX):]

class Dependency(SlotObject):
        __slots__ = ("atom", "blocker", "depth",
                "parent", "onlydeps", "priority", "root")
        def __init__(self, **kwargs):
                SlotObject.__init__(self, **kwargs)
                if self.priority is None:
                        self.priority = DepPriority()
                if self.depth is None:
                        self.depth = 0

class BlockerCache(DictMixin):
        """This caches blockers of installed packages so that dep_check does not
        have to be done for every single installed package on every invocation of
        emerge.  The cache is invalidated whenever it is detected that something
        has changed that might alter the results of dep_check() calls:
                1) the set of installed packages (including COUNTER) has changed
                2) the old-style virtuals have changed
        """

        # Number of uncached packages to trigger cache update, since
        # it's wasteful to update it for every vdb change.
        _cache_threshold = 5

        class BlockerData(object):

                __slots__ = ("__weakref__", "atoms", "counter")

                def __init__(self, counter, atoms):
                        self.counter = counter
                        self.atoms = atoms

        def __init__(self, myroot, vardb):
                self._vardb = vardb
                self._virtuals = vardb.settings.getvirtuals()
                self._cache_filename = os.path.join(myroot,
                        portage.CACHE_PATH.lstrip(os.path.sep), "vdb_blockers.pickle")
                self._cache_version = "1"
                self._cache_data = None
                self._modified = set()
                self._load()

        def _load(self):
                try:
                        f = open(self._cache_filename)
                        mypickle = pickle.Unpickler(f)
                        mypickle.find_global = None
                        self._cache_data = mypickle.load()
                        f.close()
                        del f
                except (IOError, OSError, EOFError, pickle.UnpicklingError), e:
                        if isinstance(e, pickle.UnpicklingError):
                                writemsg("!!! Error loading '%s': %s\n" % \
                                        (self._cache_filename, str(e)), noiselevel=-1)
                        del e

                cache_valid = self._cache_data and \
                        isinstance(self._cache_data, dict) and \
                        self._cache_data.get("version") == self._cache_version and \
                        isinstance(self._cache_data.get("blockers"), dict)
                if cache_valid:
                        # Validate all the atoms and counters so that
                        # corruption is detected as soon as possible.
                        invalid_items = set()
                        for k, v in self._cache_data["blockers"].iteritems():
                                if not isinstance(k, basestring):
                                        invalid_items.add(k)
                                        continue
                                try:
                                        if portage.catpkgsplit(k) is None:
                                                invalid_items.add(k)
                                                continue
                                except portage.exception.InvalidData:
                                        invalid_items.add(k)
                                        continue
                                if not isinstance(v, tuple) or \
                                        len(v) != 2:
                                        invalid_items.add(k)
                                        continue
                                counter, atoms = v
                                if not isinstance(counter, (int, long)):
                                        invalid_items.add(k)
                                        continue
                                if not isinstance(atoms, (list, tuple)):
                                        invalid_items.add(k)
                                        continue
                                invalid_atom = False
                                for atom in atoms:
                                        if not isinstance(atom, basestring):
                                                invalid_atom = True
                                                break
                                        if atom[:1] != "!" or \
                                                not portage.isvalidatom(
                                                atom, allow_blockers=True):
                                                invalid_atom = True
                                                break
                                if invalid_atom:
                                        invalid_items.add(k)
                                        continue

                        for k in invalid_items:
                                del self._cache_data["blockers"][k]
                        if not self._cache_data["blockers"]:
                                cache_valid = False

                if not cache_valid:
                        self._cache_data = {"version":self._cache_version}
                        self._cache_data["blockers"] = {}
                        self._cache_data["virtuals"] = self._virtuals
                self._modified.clear()

        def flush(self):
                """If the current user has permission and the internal blocker cache
                been updated, save it to disk and mark it unmodified.  This is called
                by emerge after it has proccessed blockers for all installed packages.
                Currently, the cache is only written if the user has superuser
                privileges (since that's required to obtain a lock), but all users
                have read access and benefit from faster blocker lookups (as long as
                the entire cache is still valid).  The cache is stored as a pickled
                dict object with the following format:

                {
                        version : "1",
                        "blockers" : {cpv1:(counter,(atom1, atom2...)), cpv2...},
                        "virtuals" : vardb.settings.getvirtuals()
                }
                """
                if len(self._modified) >= self._cache_threshold and \
                        secpass >= 2:
                        try:
                                f = portage.util.atomic_ofstream(self._cache_filename)
                                pickle.dump(self._cache_data, f, -1)
                                f.close()
                                portage.util.apply_secpass_permissions(
                                        self._cache_filename, gid=portage.portage_gid, mode=0644)
                        except (IOError, OSError), e:
                                pass
                        self._modified.clear()

        def __setitem__(self, cpv, blocker_data):
                """
                Update the cache and mark it as modified for a future call to
                self.flush().

                @param cpv: Package for which to cache blockers.
                @type cpv: String
                @param blocker_data: An object with counter and atoms attributes.
                @type blocker_data: BlockerData
                """
                self._cache_data["blockers"][cpv] = \
                        (blocker_data.counter, tuple(str(x) for x in blocker_data.atoms))
                self._modified.add(cpv)

        def __iter__(self):
                return iter(self._cache_data["blockers"])

        def __delitem__(self, cpv):
                del self._cache_data["blockers"][cpv]

        def __getitem__(self, cpv):
                """
                @rtype: BlockerData
                @returns: An object with counter and atoms attributes.
                """
                return self.BlockerData(*self._cache_data["blockers"][cpv])

        def keys(self):
                """This needs to be implemented so that self.__repr__() doesn't raise
                an AttributeError."""
                return list(self)

class BlockerDB(object):

        def __init__(self, root_config):
                self._root_config = root_config
                self._vartree = root_config.trees["vartree"]
                self._portdb = root_config.trees["porttree"].dbapi

                self._dep_check_trees = None
                self._fake_vartree = None

        def _get_fake_vartree(self, acquire_lock=0):
                fake_vartree = self._fake_vartree
                if fake_vartree is None:
                        fake_vartree = FakeVartree(self._root_config,
                                acquire_lock=acquire_lock)
                        self._fake_vartree = fake_vartree
                        self._dep_check_trees = { self._vartree.root : {
                                "porttree"    :  fake_vartree,
                                "vartree"     :  fake_vartree,
                        }}
                else:
                        fake_vartree.sync(acquire_lock=acquire_lock)
                return fake_vartree

        def findInstalledBlockers(self, new_pkg, acquire_lock=0):
                blocker_cache = BlockerCache(self._vartree.root, self._vartree.dbapi)
                dep_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
                settings = self._vartree.settings
                stale_cache = set(blocker_cache)
                fake_vartree = self._get_fake_vartree(acquire_lock=acquire_lock)
                dep_check_trees = self._dep_check_trees
                vardb = fake_vartree.dbapi
                installed_pkgs = list(vardb)

                for inst_pkg in installed_pkgs:
                        stale_cache.discard(inst_pkg.cpv)
                        cached_blockers = blocker_cache.get(inst_pkg.cpv)
                        if cached_blockers is not None and \
                                cached_blockers.counter != long(inst_pkg.metadata["COUNTER"]):
                                cached_blockers = None
                        if cached_blockers is not None:
                                blocker_atoms = cached_blockers.atoms
                        else:
                                # Use aux_get() to trigger FakeVartree global
                                # updates on *DEPEND when appropriate.
                                depstr = " ".join(vardb.aux_get(inst_pkg.cpv, dep_keys))
                                try:
                                        portage.dep._dep_check_strict = False
                                        success, atoms = portage.dep_check(depstr,
                                                vardb, settings, myuse=inst_pkg.use.enabled,
                                                trees=dep_check_trees, myroot=inst_pkg.root)
                                finally:
                                        portage.dep._dep_check_strict = True
                                if not success:
                                        pkg_location = os.path.join(inst_pkg.root,
                                                portage.VDB_PATH, inst_pkg.category, inst_pkg.pf)
                                        portage.writemsg("!!! %s/*DEPEND: %s\n" % \
                                                (pkg_location, atoms), noiselevel=-1)
                                        continue

                                blocker_atoms = [atom for atom in atoms \
                                        if atom.startswith("!")]
                                blocker_atoms.sort()
                                counter = long(inst_pkg.metadata["COUNTER"])
                                blocker_cache[inst_pkg.cpv] = \
                                        blocker_cache.BlockerData(counter, blocker_atoms)
                for cpv in stale_cache:
                        del blocker_cache[cpv]
                blocker_cache.flush()

                blocker_parents = digraph()
                blocker_atoms = []
                for pkg in installed_pkgs:
                        for blocker_atom in blocker_cache[pkg.cpv].atoms:
                                blocker_atom = blocker_atom.lstrip("!")
                                blocker_atoms.append(blocker_atom)
                                blocker_parents.add(blocker_atom, pkg)

                blocker_atoms = InternalPackageSet(initial_atoms=blocker_atoms)
                blocking_pkgs = set()
                for atom in blocker_atoms.iterAtomsForPackage(new_pkg):
                        blocking_pkgs.update(blocker_parents.parent_nodes(atom))

                # Check for blockers in the other direction.
                depstr = " ".join(new_pkg.metadata[k] for k in dep_keys)
                try:
                        portage.dep._dep_check_strict = False
                        success, atoms = portage.dep_check(depstr,
                                vardb, settings, myuse=new_pkg.use.enabled,
                                trees=dep_check_trees, myroot=new_pkg.root)
                finally:
                        portage.dep._dep_check_strict = True
                if not success:
                        # We should never get this far with invalid deps.
                        show_invalid_depstring_notice(new_pkg, depstr, atoms)
                        assert False

                blocker_atoms = [atom.lstrip("!") for atom in atoms \
                        if atom[:1] == "!"]
                if blocker_atoms:
                        blocker_atoms = InternalPackageSet(initial_atoms=blocker_atoms)
                        for inst_pkg in installed_pkgs:
                                try:
                                        blocker_atoms.iterAtomsForPackage(inst_pkg).next()
                                except (portage.exception.InvalidDependString, StopIteration):
                                        continue
                                blocking_pkgs.add(inst_pkg)

                return blocking_pkgs

def show_invalid_depstring_notice(parent_node, depstring, error_msg):

        msg1 = "\n\n!!! Invalid or corrupt dependency specification: " + \
                "\n\n%s\n\n%s\n\n%s\n\n" % (error_msg, parent_node, depstring)
        p_type, p_root, p_key, p_status = parent_node
        msg = []
        if p_status == "nomerge":
                category, pf = portage.catsplit(p_key)
                pkg_location = os.path.join(p_root, portage.VDB_PATH, category, pf)
                msg.append("Portage is unable to process the dependencies of the ")
                msg.append("'%s' package. " % p_key)
                msg.append("In order to correct this problem, the package ")
                msg.append("should be uninstalled, reinstalled, or upgraded. ")
                msg.append("As a temporary workaround, the --nodeps option can ")
                msg.append("be used to ignore all dependencies.  For reference, ")
                msg.append("the problematic dependencies can be found in the ")
                msg.append("*DEPEND files located in '%s/'." % pkg_location)
        else:
                msg.append("This package can not be installed. ")
                msg.append("Please notify the '%s' package maintainer " % p_key)
                msg.append("about this problem.")

        msg2 = "".join("%s\n" % line for line in textwrap.wrap("".join(msg), 72))
        writemsg_level(msg1 + msg2, level=logging.ERROR, noiselevel=-1)

class PackageVirtualDbapi(portage.dbapi):
        """
        A dbapi-like interface class that represents the state of the installed
        package database as new packages are installed, replacing any packages
        that previously existed in the same slot. The main difference between
        this class and fakedbapi is that this one uses Package instances
        internally (passed in via cpv_inject() and cpv_remove() calls).
        """
        def __init__(self, settings):
                portage.dbapi.__init__(self)
                self.settings = settings
                self._match_cache = {}
                self._cp_map = {}
                self._cpv_map = {}

        def clear(self):
                """
                Remove all packages.
                """
                if self._cpv_map:
                        self._clear_cache()
                        self._cp_map.clear()
                        self._cpv_map.clear()

        def copy(self):
                obj = PackageVirtualDbapi(self.settings)
                obj._match_cache = self._match_cache.copy()
                obj._cp_map = self._cp_map.copy()
                for k, v in obj._cp_map.iteritems():
                        obj._cp_map[k] = v[:]
                obj._cpv_map = self._cpv_map.copy()
                return obj

        def __iter__(self):
                return self._cpv_map.itervalues()

        def __contains__(self, item):
                existing = self._cpv_map.get(item.cpv)
                if existing is not None and \
                        existing == item:
                        return True
                return False

        def get(self, item, default=None):
                cpv = getattr(item, "cpv", None)
                if cpv is None:
                        if len(item) != 4:
                                return default
                        type_name, root, cpv, operation = item

                existing = self._cpv_map.get(cpv)
                if existing is not None and \
                        existing == item:
                        return existing
                return default

        def match_pkgs(self, atom):
                return [self._cpv_map[cpv] for cpv in self.match(atom)]

        def _clear_cache(self):
                if self._categories is not None:
                        self._categories = None
                if self._match_cache:
                        self._match_cache = {}

        def match(self, origdep, use_cache=1):
                result = self._match_cache.get(origdep)
                if result is not None:
                        return result[:]
                result = portage.dbapi.match(self, origdep, use_cache=use_cache)
                self._match_cache[origdep] = result
                return result[:]

        def cpv_exists(self, cpv):
                return cpv in self._cpv_map

        def cp_list(self, mycp, use_cache=1):
                cachelist = self._match_cache.get(mycp)
                # cp_list() doesn't expand old-style virtuals
                if cachelist and cachelist[0].startswith(mycp):
                        return cachelist[:]
                cpv_list = self._cp_map.get(mycp)
                if cpv_list is None:
                        cpv_list = []
                else:
                        cpv_list = [pkg.cpv for pkg in cpv_list]
                self._cpv_sort_ascending(cpv_list)
                if not (not cpv_list and mycp.startswith("virtual/")):
                        self._match_cache[mycp] = cpv_list
                return cpv_list[:]

        def cp_all(self):
                return list(self._cp_map)

        def cpv_all(self):
                return list(self._cpv_map)

        def cpv_inject(self, pkg):
                cp_list = self._cp_map.get(pkg.cp)
                if cp_list is None:
                        cp_list = []
                        self._cp_map[pkg.cp] = cp_list
                e_pkg = self._cpv_map.get(pkg.cpv)
                if e_pkg is not None:
                        if e_pkg == pkg:
                                return
                        self.cpv_remove(e_pkg)
                for e_pkg in cp_list:
                        if e_pkg.slot_atom == pkg.slot_atom:
                                if e_pkg == pkg:
                                        return
                                self.cpv_remove(e_pkg)
                                break
                cp_list.append(pkg)
                self._cpv_map[pkg.cpv] = pkg
                self._clear_cache()

        def cpv_remove(self, pkg):
                old_pkg = self._cpv_map.get(pkg.cpv)
                if old_pkg != pkg:
                        raise KeyError(pkg)
                self._cp_map[pkg.cp].remove(pkg)
                del self._cpv_map[pkg.cpv]
                self._clear_cache()

        def aux_get(self, cpv, wants):
                metadata = self._cpv_map[cpv].metadata
                return [metadata.get(x, "") for x in wants]

        def aux_update(self, cpv, values):
                self._cpv_map[cpv].metadata.update(values)
                self._clear_cache()

class depgraph(object):

        pkg_tree_map = RootConfig.pkg_tree_map

        _dep_keys = ["DEPEND", "RDEPEND", "PDEPEND"]

        def __init__(self, settings, trees, myopts, myparams, spinner):
                self.settings = settings
                self.target_root = settings["ROOT"]
                self.myopts = myopts
                self.myparams = myparams
                self.edebug = 0
                if settings.get("PORTAGE_DEBUG", "") == "1":
                        self.edebug = 1
                self.spinner = spinner
                self._running_root = trees["/"]["root_config"]
                self._opts_no_restart = Scheduler._opts_no_restart
                self.pkgsettings = {}
                # Maps slot atom to package for each Package added to the graph.
                self._slot_pkg_map = {}
                # Maps nodes to the reasons they were selected for reinstallation.
                self._reinstall_nodes = {}
                self.mydbapi = {}
                self.trees = {}
                self._trees_orig = trees
                self.roots = {}
                # Contains a filtered view of preferred packages that are selected
                # from available repositories.
                self._filtered_trees = {}
                # Contains installed packages and new packages that have been added
                # to the graph.
                self._graph_trees = {}
                # All Package instances
                self._pkg_cache = self._package_cache(self)
                for myroot in trees:
                        self.trees[myroot] = {}
                        # Create a RootConfig instance that references
                        # the FakeVartree instead of the real one.
                        self.roots[myroot] = RootConfig(
                                trees[myroot]["vartree"].settings,
                                self.trees[myroot],
                                trees[myroot]["root_config"].setconfig)
                        for tree in ("porttree", "bintree"):
                                self.trees[myroot][tree] = trees[myroot][tree]
                        self.trees[myroot]["vartree"] = \
                                FakeVartree(trees[myroot]["root_config"],
                                        pkg_cache=self._pkg_cache)
                        self.pkgsettings[myroot] = portage.config(
                                clone=self.trees[myroot]["vartree"].settings)
                        self._slot_pkg_map[myroot] = {}
                        vardb = self.trees[myroot]["vartree"].dbapi
                        preload_installed_pkgs = "--nodeps" not in self.myopts and \
                                "--buildpkgonly" not in self.myopts
                        # This fakedbapi instance will model the state that the vdb will
                        # have after new packages have been installed.
                        fakedb = PackageVirtualDbapi(vardb.settings)
                        if preload_installed_pkgs:
                                for pkg in vardb:
                                        self.spinner.update()
                                        # This triggers metadata updates via FakeVartree.
                                        vardb.aux_get(pkg.cpv, [])
                                        fakedb.cpv_inject(pkg)

                        # Now that the vardb state is cached in our FakeVartree,
                        # we won't be needing the real vartree cache for awhile.
                        # To make some room on the heap, clear the vardbapi
                        # caches.
                        trees[myroot]["vartree"].dbapi._clear_cache()
                        gc.collect()

                        self.mydbapi[myroot] = fakedb
                        def graph_tree():
                                pass
                        graph_tree.dbapi = fakedb
                        self._graph_trees[myroot] = {}
                        self._filtered_trees[myroot] = {}
                        # Substitute the graph tree for the vartree in dep_check() since we
                        # want atom selections to be consistent with package selections
                        # have already been made.
                        self._graph_trees[myroot]["porttree"]   = graph_tree
                        self._graph_trees[myroot]["vartree"]    = graph_tree
                        def filtered_tree():
                                pass
                        filtered_tree.dbapi = self._dep_check_composite_db(self, myroot)
                        self._filtered_trees[myroot]["porttree"] = filtered_tree

                        # Passing in graph_tree as the vartree here could lead to better
                        # atom selections in some cases by causing atoms for packages that
                        # have been added to the graph to be preferred over other choices.
                        # However, it can trigger atom selections that result in
                        # unresolvable direct circular dependencies. For example, this
                        # happens with gwydion-dylan which depends on either itself or
                        # gwydion-dylan-bin. In case gwydion-dylan is not yet installed,
                        # gwydion-dylan-bin needs to be selected in order to avoid a
                        # an unresolvable direct circular dependency.
                        #
                        # To solve the problem described above, pass in "graph_db" so that
                        # packages that have been added to the graph are distinguishable
                        # from other available packages and installed packages. Also, pass
                        # the parent package into self._select_atoms() calls so that
                        # unresolvable direct circular dependencies can be detected and
                        # avoided when possible.
                        self._filtered_trees[myroot]["graph_db"] = graph_tree.dbapi
                        self._filtered_trees[myroot]["vartree"] = self.trees[myroot]["vartree"]

                        dbs = []
                        portdb = self.trees[myroot]["porttree"].dbapi
                        bindb  = self.trees[myroot]["bintree"].dbapi
                        vardb  = self.trees[myroot]["vartree"].dbapi
                        #               (db, pkg_type, built, installed, db_keys)
                        if "--usepkgonly" not in self.myopts:
                                db_keys = list(portdb._aux_cache_keys)
                                dbs.append((portdb, "ebuild", False, False, db_keys))
                        if "--usepkg" in self.myopts:
                                db_keys = list(bindb._aux_cache_keys)
                                dbs.append((bindb,  "binary", True, False, db_keys))
                        db_keys = list(trees[myroot]["vartree"].dbapi._aux_cache_keys)
                        dbs.append((vardb, "installed", True, True, db_keys))
                        self._filtered_trees[myroot]["dbs"] = dbs
                        if "--usepkg" in self.myopts:
                                self.trees[myroot]["bintree"].populate(
                                        "--getbinpkg" in self.myopts,
                                        "--getbinpkgonly" in self.myopts)
                del trees

                self.digraph=portage.digraph()
                # contains all sets added to the graph
                self._sets = {}
                # contains atoms given as arguments
                self._sets["args"] = InternalPackageSet()
                # contains all atoms from all sets added to the graph, including
                # atoms given as arguments
                self._set_atoms = InternalPackageSet()
                self._atom_arg_map = {}
                # contains all nodes pulled in by self._set_atoms
                self._set_nodes = set()
                # Contains only Blocker -> Uninstall edges
                self._blocker_uninstalls = digraph()
                # Contains only Package -> Blocker edges
                self._blocker_parents = digraph()
                # Contains only irrelevant Package -> Blocker edges
                self._irrelevant_blockers = digraph()
                # Contains only unsolvable Package -> Blocker edges
                self._unsolvable_blockers = digraph()
                self._slot_collision_info = {}
                # Slot collision nodes are not allowed to block other packages since
                # blocker validation is only able to account for one package per slot.
                self._slot_collision_nodes = set()
                self._parent_atoms = {}
                self._slot_conflict_parent_atoms = set()
                self._serialized_tasks_cache = None
                self._scheduler_graph = None
                self._displayed_list = None
                self._pprovided_args = []
                self._missing_args = []
                self._masked_installed = set()
                self._unsatisfied_deps_for_display = []
                self._unsatisfied_blockers_for_display = None
                self._circular_deps_for_display = None
                self._dep_stack = []
                self._unsatisfied_deps = []
                self._initially_unsatisfied_deps = []
                self._ignored_deps = []
                self._required_set_names = set(["system", "world"])
                self._select_atoms = self._select_atoms_highest_available
                self._select_package = self._select_pkg_highest_available
                self._highest_pkg_cache = {}

        def _show_slot_collision_notice(self):
                """Show an informational message advising the user to mask one of the
                the packages. In some cases it may be possible to resolve this
                automatically, but support for backtracking (removal nodes that have
                already been selected) will be required in order to handle all possible
                cases.
                """

                if not self._slot_collision_info:
                        return

                self._show_merge_list()

                msg = []
                msg.append("\n!!! Multiple package instances within a single " + \
                        "package slot have been pulled\n")
                msg.append("!!! into the dependency graph, resulting" + \
                        " in a slot conflict:\n\n")
                indent = "  "
                # Max number of parents shown, to avoid flooding the display.
                max_parents = 3
                explanation_columns = 70
                explanations = 0
                for (slot_atom, root), slot_nodes \
                        in self._slot_collision_info.iteritems():
                        msg.append(str(slot_atom))
                        msg.append("\n\n")

                        for node in slot_nodes:
                                msg.append(indent)
                                msg.append(str(node))
                                parent_atoms = self._parent_atoms.get(node)
                                if parent_atoms:
                                        pruned_list = set()
                                        # Prefer conflict atoms over others.
                                        for parent_atom in parent_atoms:
                                                if len(pruned_list) >= max_parents:
                                                        break
                                                if parent_atom in self._slot_conflict_parent_atoms:
                                                        pruned_list.add(parent_atom)

                                        # If this package was pulled in by conflict atoms then
                                        # show those alone since those are the most interesting.
                                        if not pruned_list:
                                                # When generating the pruned list, prefer instances
                                                # of DependencyArg over instances of Package.
                                                for parent_atom in parent_atoms:
                                                        if len(pruned_list) >= max_parents:
                                                                break
                                                        parent, atom = parent_atom
                                                        if isinstance(parent, DependencyArg):
                                                                pruned_list.add(parent_atom)
                                                # Prefer Packages instances that themselves have been
                                                # pulled into collision slots.
                                                for parent_atom in parent_atoms:
                                                        if len(pruned_list) >= max_parents:
                                                                break
                                                        parent, atom = parent_atom
                                                        if isinstance(parent, Package) and \
                                                                (parent.slot_atom, parent.root) \
                                                                in self._slot_collision_info:
                                                                pruned_list.add(parent_atom)
                                                for parent_atom in parent_atoms:
                                                        if len(pruned_list) >= max_parents:
                                                                break
                                                        pruned_list.add(parent_atom)
                                        omitted_parents = len(parent_atoms) - len(pruned_list)
                                        parent_atoms = pruned_list
                                        msg.append(" pulled in by\n")
                                        for parent_atom in parent_atoms:
                                                parent, atom = parent_atom
                                                msg.append(2*indent)
                                                if isinstance(parent,
                                                        (PackageArg, AtomArg)):
                                                        # For PackageArg and AtomArg types, it's
                                                        # redundant to display the atom attribute.
                                                        msg.append(str(parent))
                                                else:
                                                        # Display the specific atom from SetArg or
                                                        # Package types.
                                                        msg.append("%s required by %s" % (atom, parent))
                                                msg.append("\n")
                                        if omitted_parents:
                                                msg.append(2*indent)
                                                msg.append("(and %d more)\n" % omitted_parents)
                                else:
                                        msg.append(" (no parents)\n")
                                msg.append("\n")
                        explanation = self._slot_conflict_explanation(slot_nodes)
                        if explanation:
                                explanations += 1
                                msg.append(indent + "Explanation:\n\n")
                                for line in textwrap.wrap(explanation, explanation_columns):
                                        msg.append(2*indent + line + "\n")
                                msg.append("\n")
                msg.append("\n")
                sys.stderr.write("".join(msg))
                sys.stderr.flush()

                explanations_for_all = explanations == len(self._slot_collision_info)

                if explanations_for_all or "--quiet" in self.myopts:
                        return

                msg = []
                msg.append("It may be possible to solve this problem ")
                msg.append("by using package.mask to prevent one of ")
                msg.append("those packages from being selected. ")
                msg.append("However, it is also possible that conflicting ")
                msg.append("dependencies exist such that they are impossible to ")
                msg.append("satisfy simultaneously.  If such a conflict exists in ")
                msg.append("the dependencies of two different packages, then those ")
                msg.append("packages can not be installed simultaneously.")

                from formatter import AbstractFormatter, DumbWriter
                f = AbstractFormatter(DumbWriter(sys.stderr, maxcol=72))
                for x in msg:
                        f.add_flowing_data(x)
                f.end_paragraph(1)

                msg = []
                msg.append("For more information, see MASKED PACKAGES ")
                msg.append("section in the emerge man page or refer ")
                msg.append("to the Gentoo Handbook.")
                for x in msg:
                        f.add_flowing_data(x)
                f.end_paragraph(1)
                f.writer.flush()

        def _slot_conflict_explanation(self, slot_nodes):
                """
                When a slot conflict occurs due to USE deps, there are a few
                different cases to consider:

                1) New USE are correctly set but --newuse wasn't requested so an
                   installed package with incorrect USE happened to get pulled
                   into graph before the new one.

                2) New USE are incorrectly set but an installed package has correct
                   USE so it got pulled into the graph, and a new instance also got
                   pulled in due to --newuse or an upgrade.

                3) Multiple USE deps exist that can't be satisfied simultaneously,
                   and multiple package instances got pulled into the same slot to
                   satisfy the conflicting deps.

                Currently, explanations and suggested courses of action are generated
                for cases 1 and 2. Case 3 is too complex to give a useful suggestion.
                """

                if len(slot_nodes) != 2:
                        # Suggestions are only implemented for
                        # conflicts between two packages.
                        return None

                all_conflict_atoms = self._slot_conflict_parent_atoms
                matched_node = None
                matched_atoms = None
                unmatched_node = None
                for node in slot_nodes:
                        parent_atoms = self._parent_atoms.get(node)
                        if not parent_atoms:
                                # Normally, there are always parent atoms. If there are
                                # none then something unexpected is happening and there's
                                # currently no suggestion for this case.
                                return None
                        conflict_atoms = all_conflict_atoms.intersection(parent_atoms)
                        for parent_atom in conflict_atoms:
                                parent, atom = parent_atom
                                if not atom.use:
                                        # Suggestions are currently only implemented for cases
                                        # in which all conflict atoms have USE deps.
                                        return None
                        if conflict_atoms:
                                if matched_node is not None:
                                        # If conflict atoms match multiple nodes
                                        # then there's no suggestion.
                                        return None
                                matched_node = node
                                matched_atoms = conflict_atoms
                        else:
                                if unmatched_node is not None:
                                        # Neither node is matched by conflict atoms, and
                                        # there is no suggestion for this case.
                                        return None
                                unmatched_node = node

                if matched_node is None or unmatched_node is None:
                        # This shouldn't happen.
                        return None

                if unmatched_node.installed and not matched_node.installed:
                        return "New USE are correctly set, but --newuse wasn't" + \
                                " requested, so an installed package with incorrect USE " + \
                                "happened to get pulled into the dependency graph. " + \
                                "In order to solve " + \
                                "this, either specify the --newuse option or explicitly " + \
                                " reinstall '%s'." % matched_node.slot_atom

                if matched_node.installed and not unmatched_node.installed:
                        atoms = sorted(set(atom for parent, atom in matched_atoms))
                        explanation = ("New USE for '%s' are incorrectly set. " + \
                                "In order to solve this, adjust USE to satisfy '%s'") % \
                                (matched_node.slot_atom, atoms[0])
                        if len(atoms) > 1:
                                for atom in atoms[1:-1]:
                                        explanation += ", '%s'" % (atom,)
                                if len(atoms) > 2:
                                        explanation += ","
                                explanation += " and '%s'" % (atoms[-1],)
                        explanation += "."
                        return explanation

                return None

        def _process_slot_conflicts(self):
                """
                Process slot conflict data to identify specific atoms which
                lead to conflict. These atoms only match a subset of the
                packages that have been pulled into a given slot.
                """
                for (slot_atom, root), slot_nodes \
                        in self._slot_collision_info.iteritems():

                        all_parent_atoms = set()
                        for pkg in slot_nodes:
                                parent_atoms = self._parent_atoms.get(pkg)
                                if not parent_atoms:
                                        continue
                                all_parent_atoms.update(parent_atoms)

                        for pkg in slot_nodes:
                                parent_atoms = self._parent_atoms.get(pkg)
                                if parent_atoms is None:
                                        parent_atoms = set()
                                        self._parent_atoms[pkg] = parent_atoms
                                for parent_atom in all_parent_atoms:
                                        if parent_atom in parent_atoms:
                                                continue
                                        # Use package set for matching since it will match via
                                        # PROVIDE when necessary, while match_from_list does not.
                                        parent, atom = parent_atom
                                        atom_set = InternalPackageSet(
                                                initial_atoms=(atom,))
                                        if atom_set.findAtomForPackage(pkg):
                                                parent_atoms.add(parent_atom)
                                        else:
                                                self._slot_conflict_parent_atoms.add(parent_atom)

        def _reinstall_for_flags(self, forced_flags,
                orig_use, orig_iuse, cur_use, cur_iuse):
                """Return a set of flags that trigger reinstallation, or None if there
                are no such flags."""
                if "--newuse" in self.myopts:
                        flags = set(orig_iuse.symmetric_difference(
                                cur_iuse).difference(forced_flags))
                        flags.update(orig_iuse.intersection(orig_use).symmetric_difference(
                                cur_iuse.intersection(cur_use)))
                        if flags:
                                return flags
                elif "changed-use" == self.myopts.get("--reinstall"):
                        flags = orig_iuse.intersection(orig_use).symmetric_difference(
                                cur_iuse.intersection(cur_use))
                        if flags:
                                return flags
                return None

        def _create_graph(self, allow_unsatisfied=False):
                dep_stack = self._dep_stack
                while dep_stack:
                        self.spinner.update()
                        dep = dep_stack.pop()
                        if isinstance(dep, Package):
                                if not self._add_pkg_deps(dep,
                                        allow_unsatisfied=allow_unsatisfied):
                                        return 0
                                continue
                        if not self._add_dep(dep, allow_unsatisfied=allow_unsatisfied):
                                return 0
                return 1

        def _add_dep(self, dep, allow_unsatisfied=False):
                debug = "--debug" in self.myopts
                buildpkgonly = "--buildpkgonly" in self.myopts
                nodeps = "--nodeps" in self.myopts
                empty = "empty" in self.myparams
                deep = "deep" in self.myparams
                update = "--update" in self.myopts and dep.depth <= 1
                if dep.blocker:
                        if not buildpkgonly and \
                                not nodeps and \
                                dep.parent not in self._slot_collision_nodes:
                                if dep.parent.onlydeps:
                                        # It's safe to ignore blockers if the
                                        # parent is an --onlydeps node.
                                        return 1
                                # The blocker applies to the root where
                                # the parent is or will be installed.
                                blocker = Blocker(atom=dep.atom,
                                        eapi=dep.parent.metadata["EAPI"],
                                        root=dep.parent.root)
                                self._blocker_parents.add(blocker, dep.parent)
                        return 1
                dep_pkg, existing_node = self._select_package(dep.root, dep.atom,
                        onlydeps=dep.onlydeps)
                if not dep_pkg:
                        if allow_unsatisfied:
                                self._unsatisfied_deps.append(dep)
                                return 1
                        self._unsatisfied_deps_for_display.append(
                                ((dep.root, dep.atom), {"myparent":dep.parent}))
                        return 0
                # In some cases, dep_check will return deps that shouldn't
                # be proccessed any further, so they are identified and
                # discarded here. Try to discard as few as possible since
                # discarded dependencies reduce the amount of information
                # available for optimization of merge order.
                if dep.priority.satisfied and \
                        not (existing_node or empty or deep or update):
                        myarg = None
                        if dep.root == self.target_root:
                                try:
                                        myarg = self._iter_atoms_for_pkg(dep_pkg).next()
                                except StopIteration:
                                        pass
                                except portage.exception.InvalidDependString:
                                        if not dep_pkg.installed:
                                                # This shouldn't happen since the package
                                                # should have been masked.
                                                raise
                        if not myarg:
                                self._ignored_deps.append(dep)
                                return 1

                if not self._add_pkg(dep_pkg, dep):
                        return 0
                return 1

        def _add_pkg(self, pkg, dep):
                myparent = None
                priority = None
                depth = 0
                if dep is None:
                        dep = Dependency()
                else:
                        myparent = dep.parent
                        priority = dep.priority
                        depth = dep.depth
                if priority is None:
                        priority = DepPriority()
                """
                Fills the digraph with nodes comprised of packages to merge.
                mybigkey is the package spec of the package to merge.
                myparent is the package depending on mybigkey ( or None )
                addme = Should we add this package to the digraph or are we just looking at it's deps?
                        Think --onlydeps, we need to ignore packages in that case.
                #stuff to add:
                #SLOT-aware emerge
                #IUSE-aware emerge -> USE DEP aware depgraph
                #"no downgrade" emerge
                """
                # Ensure that the dependencies of the same package
                # are never processed more than once.
                previously_added = pkg in self.digraph

                # select the correct /var database that we'll be checking against
                vardbapi = self.trees[pkg.root]["vartree"].dbapi
                pkgsettings = self.pkgsettings[pkg.root]

                arg_atoms = None
                if True:
                        try:
                                arg_atoms = list(self._iter_atoms_for_pkg(pkg))
                        except portage.exception.InvalidDependString, e:
                                if not pkg.installed:
                                        show_invalid_depstring_notice(
                                                pkg, pkg.metadata["PROVIDE"], str(e))
                                        return 0
                                del e

                if not pkg.onlydeps:
                        if not pkg.installed and \
                                "empty" not in self.myparams and \
                                vardbapi.match(pkg.slot_atom):
                                # Increase the priority of dependencies on packages that
                                # are being rebuilt. This optimizes merge order so that
                                # dependencies are rebuilt/updated as soon as possible,
                                # which is needed especially when emerge is called by
                                # revdep-rebuild since dependencies may be affected by ABI
                                # breakage that has rendered them useless. Don't adjust
                                # priority here when in "empty" mode since all packages
                                # are being merged in that case.
                                priority.rebuild = True

                        existing_node = self._slot_pkg_map[pkg.root].get(pkg.slot_atom)
                        slot_collision = False
                        if existing_node:
                                existing_node_matches = pkg.cpv == existing_node.cpv
                                if existing_node_matches and \
                                        pkg != existing_node and \
                                        dep.atom is not None:
                                        # Use package set for matching since it will match via
                                        # PROVIDE when necessary, while match_from_list does not.
                                        atom_set = InternalPackageSet(initial_atoms=[dep.atom])
                                        if not atom_set.findAtomForPackage(existing_node):
                                                existing_node_matches = False
                                if existing_node_matches:
                                        # The existing node can be reused.
                                        if arg_atoms:
                                                for parent_atom in arg_atoms:
                                                        parent, atom = parent_atom
                                                        self.digraph.add(existing_node, parent,
                                                                priority=priority)
                                                        self._add_parent_atom(existing_node, parent_atom)
                                        # If a direct circular dependency is not an unsatisfied
                                        # buildtime dependency then drop it here since otherwise
                                        # it can skew the merge order calculation in an unwanted
                                        # way.
                                        if existing_node != myparent or \
                                                (priority.buildtime and not priority.satisfied):
                                                self.digraph.addnode(existing_node, myparent,
                                                        priority=priority)
                                                if dep.atom is not None and dep.parent is not None:
                                                        self._add_parent_atom(existing_node,
                                                                (dep.parent, dep.atom))
                                        return 1
                                else:

                                        # A slot collision has occurred.  Sometimes this coincides
                                        # with unresolvable blockers, so the slot collision will be
                                        # shown later if there are no unresolvable blockers.
                                        self._add_slot_conflict(pkg)
                                        slot_collision = True

                        if slot_collision:
                                # Now add this node to the graph so that self.display()
                                # can show use flags and --tree portage.output.  This node is
                                # only being partially added to the graph.  It must not be
                                # allowed to interfere with the other nodes that have been
                                # added.  Do not overwrite data for existing nodes in
                                # self.mydbapi since that data will be used for blocker
                                # validation.
                                # Even though the graph is now invalid, continue to process
                                # dependencies so that things like --fetchonly can still
                                # function despite collisions.
                                pass
                        else:
                                self._slot_pkg_map[pkg.root][pkg.slot_atom] = pkg
                                self.mydbapi[pkg.root].cpv_inject(pkg)

                        if not pkg.installed:
                                # Allow this package to satisfy old-style virtuals in case it
                                # doesn't already. Any pre-existing providers will be preferred
                                # over this one.
                                try:
                                        pkgsettings.setinst(pkg.cpv, pkg.metadata)
                                        # For consistency, also update the global virtuals.
                                        settings = self.roots[pkg.root].settings
                                        settings.unlock()
                                        settings.setinst(pkg.cpv, pkg.metadata)
                                        settings.lock()
                                except portage.exception.InvalidDependString, e:
                                        show_invalid_depstring_notice(
                                                pkg, pkg.metadata["PROVIDE"], str(e))
                                        del e
                                        return 0

                if arg_atoms:
                        self._set_nodes.add(pkg)

                # Do this even when addme is False (--onlydeps) so that the
                # parent/child relationship is always known in case
                # self._show_slot_collision_notice() needs to be called later.
                self.digraph.add(pkg, myparent, priority=priority)
                if dep.atom is not None and dep.parent is not None:
                        self._add_parent_atom(pkg, (dep.parent, dep.atom))

                if arg_atoms:
                        for parent_atom in arg_atoms:
                                parent, atom = parent_atom
                                self.digraph.add(pkg, parent, priority=priority)
                                self._add_parent_atom(pkg, parent_atom)

                """ This section determines whether we go deeper into dependencies or not.
                    We want to go deeper on a few occasions:
                    Installing package A, we need to make sure package A's deps are met.
                    emerge --deep <pkgspec>; we need to recursively check dependencies of pkgspec
                    If we are in --nodeps (no recursion) mode, we obviously only check 1 level of dependencies.
                """
                dep_stack = self._dep_stack
                if "recurse" not in self.myparams:
                        return 1
                elif pkg.installed and \
                        "deep" not in self.myparams:
                        dep_stack = self._ignored_deps

                self.spinner.update()

                if arg_atoms:
                        depth = 0
                pkg.depth = depth
                if not previously_added:
                        dep_stack.append(pkg)
                return 1

        def _add_parent_atom(self, pkg, parent_atom):
                parent_atoms = self._parent_atoms.get(pkg)
                if parent_atoms is None:
                        parent_atoms = set()
                        self._parent_atoms[pkg] = parent_atoms
                parent_atoms.add(parent_atom)

        def _add_slot_conflict(self, pkg):
                self._slot_collision_nodes.add(pkg)
                slot_key = (pkg.slot_atom, pkg.root)
                slot_nodes = self._slot_collision_info.get(slot_key)
                if slot_nodes is None:
                        slot_nodes = set()
                        slot_nodes.add(self._slot_pkg_map[pkg.root][pkg.slot_atom])
                        self._slot_collision_info[slot_key] = slot_nodes
                slot_nodes.add(pkg)

        def _add_pkg_deps(self, pkg, allow_unsatisfied=False):

                mytype = pkg.type_name
                myroot = pkg.root
                mykey = pkg.cpv
                metadata = pkg.metadata
                myuse = pkg.use.enabled
                jbigkey = pkg
                depth = pkg.depth + 1
                removal_action = "remove" in self.myparams

                edepend={}
                depkeys = ["DEPEND","RDEPEND","PDEPEND"]
                for k in depkeys:
                        edepend[k] = metadata[k]

                if not pkg.built and \
                        "--buildpkgonly" in self.myopts and \
                        "deep" not in self.myparams and \
                        "empty" not in self.myparams:
                        edepend["RDEPEND"] = ""
                        edepend["PDEPEND"] = ""
                bdeps_satisfied = False
                
                if pkg.built and not removal_action:
                        if self.myopts.get("--with-bdeps", "n") == "y":
                                # Pull in build time deps as requested, but marked them as
                                # "satisfied" since they are not strictly required. This allows
                                # more freedom in the merge order calculation for solving
                                # circular dependencies. Don't convert to PDEPEND since that
                                # could make --with-bdeps=y less effective if it is used to
                                # adjust merge order to prevent built_with_use() calls from
                                # failing.
                                bdeps_satisfied = True
                        else:
                                # built packages do not have build time dependencies.
                                edepend["DEPEND"] = ""

                if removal_action and self.myopts.get("--with-bdeps", "y") == "n":
                        edepend["DEPEND"] = ""

                deps = (
                        ("/", edepend["DEPEND"],
                                self._priority(buildtime=True, satisfied=bdeps_satisfied)),
                        (myroot, edepend["RDEPEND"], self._priority(runtime=True)),
                        (myroot, edepend["PDEPEND"], self._priority(runtime_post=True))
                )

                debug = "--debug" in self.myopts
                strict = mytype != "installed"
                try:
                        for dep_root, dep_string, dep_priority in deps:
                                if pkg.onlydeps:
                                        # Decrease priority so that --buildpkgonly
                                        # hasallzeros() works correctly.
                                        dep_priority = DepPriority()
                                if not dep_string:
                                        continue
                                if debug:
                                        print
                                        print "Parent:   ", jbigkey
                                        print "Depstring:", dep_string
                                        print "Priority:", dep_priority
                                vardb = self.roots[dep_root].trees["vartree"].dbapi
                                try:
                                        selected_atoms = self._select_atoms(dep_root,
                                                dep_string, myuse=myuse, parent=pkg, strict=strict)
                                except portage.exception.InvalidDependString, e:
                                        show_invalid_depstring_notice(jbigkey, dep_string, str(e))
                                        return 0
                                if debug:
                                        print "Candidates:", selected_atoms

                                for atom in selected_atoms:
                                        try:

                                                atom = portage.dep.Atom(atom)

                                                mypriority = dep_priority.copy()
                                                if not atom.blocker and vardb.match(atom):
                                                        mypriority.satisfied = True

                                                if not self._add_dep(Dependency(atom=atom,
                                                        blocker=atom.blocker, depth=depth, parent=pkg,
                                                        priority=mypriority, root=dep_root),
                                                        allow_unsatisfied=allow_unsatisfied):
                                                        return 0

                                        except portage.exception.InvalidAtom, e:
                                                show_invalid_depstring_notice(
                                                        pkg, dep_string, str(e))
                                                del e
                                                if not pkg.installed:
                                                        return 0

                                if debug:
                                        print "Exiting...", jbigkey
                except portage.exception.AmbiguousPackageName, e:
                        pkgs = e.args[0]
                        portage.writemsg("\n\n!!! An atom in the dependencies " + \
                                "is not fully-qualified. Multiple matches:\n\n", noiselevel=-1)
                        for cpv in pkgs:
                                portage.writemsg("    %s\n" % cpv, noiselevel=-1)
                        portage.writemsg("\n", noiselevel=-1)
                        if mytype == "binary":
                                portage.writemsg(
                                        "!!! This binary package cannot be installed: '%s'\n" % \
                                        mykey, noiselevel=-1)
                        elif mytype == "ebuild":
                                portdb = self.roots[myroot].trees["porttree"].dbapi
                                myebuild, mylocation = portdb.findname2(mykey)
                                portage.writemsg("!!! This ebuild cannot be installed: " + \
                                        "'%s'\n" % myebuild, noiselevel=-1)
                        portage.writemsg("!!! Please notify the package maintainer " + \
                                "that atoms must be fully-qualified.\n", noiselevel=-1)
                        return 0
                return 1

        def _priority(self, **kwargs):
                if "remove" in self.myparams:
                        priority_constructor = UnmergeDepPriority
                else:
                        priority_constructor = DepPriority
                return priority_constructor(**kwargs)

        def _dep_expand(self, root_config, atom_without_category):
                """
                @param root_config: a root config instance
                @type root_config: RootConfig
                @param atom_without_category: an atom without a category component
                @type atom_without_category: String
                @rtype: list
                @returns: a list of atoms containing categories (possibly empty)
                """
                null_cp = portage.dep_getkey(insert_category_into_atom(
                        atom_without_category, "null"))
                cat, atom_pn = portage.catsplit(null_cp)

                cp_set = set()
                for db, pkg_type, built, installed, db_keys in \
                        self._filtered_trees[root_config.root]["dbs"]:
                        cp_set.update(db.cp_all())
                for cp in list(cp_set):
                        cat, pn = portage.catsplit(cp)
                        if pn != atom_pn:
                                cp_set.discard(cp)
                deps = []
                for cp in cp_set:
                        cat, pn = portage.catsplit(cp)
                        deps.append(insert_category_into_atom(
                                atom_without_category, cat))
                return deps

        def _have_new_virt(self, root, atom_cp):
                ret = False
                for db, pkg_type, built, installed, db_keys in \
                        self._filtered_trees[root]["dbs"]:
                        if db.cp_list(atom_cp):
                                ret = True
                                break
                return ret

        def _iter_atoms_for_pkg(self, pkg):
                # TODO: add multiple $ROOT support
                if pkg.root != self.target_root:
                        return
                atom_arg_map = self._atom_arg_map
                root_config = self.roots[pkg.root]
                for atom in self._set_atoms.iterAtomsForPackage(pkg):
                        atom_cp = portage.dep_getkey(atom)
                        if atom_cp != pkg.cp and \
                                self._have_new_virt(pkg.root, atom_cp):
                                continue
                        visible_pkgs = root_config.visible_pkgs.match_pkgs(atom)
                        visible_pkgs.reverse() # descending order
                        higher_slot = None
                        for visible_pkg in visible_pkgs:
                                if visible_pkg.cp != atom_cp:
                                        continue
                                if pkg >= visible_pkg:
                                        # This is descending order, and we're not
                                        # interested in any versions <= pkg given.
                                        break
                                if pkg.slot_atom != visible_pkg.slot_atom:
                                        higher_slot = visible_pkg
                                        break
                        if higher_slot is not None:
                                continue
                        for arg in atom_arg_map[(atom, pkg.root)]:
                                if isinstance(arg, PackageArg) and \
                                        arg.package != pkg:
                                        continue
                                yield arg, atom

        def select_files(self, myfiles):
                """Given a list of .tbz2s, .ebuilds sets, and deps, create the
                appropriate depgraph and return a favorite list."""
                debug = "--debug" in self.myopts
                root_config = self.roots[self.target_root]
                sets = root_config.sets
                getSetAtoms = root_config.setconfig.getSetAtoms
                myfavorites=[]
                myroot = self.target_root
                dbs = self._filtered_trees[myroot]["dbs"]
                vardb = self.trees[myroot]["vartree"].dbapi
                real_vardb = self._trees_orig[myroot]["vartree"].dbapi
                portdb = self.trees[myroot]["porttree"].dbapi
                bindb = self.trees[myroot]["bintree"].dbapi
                pkgsettings = self.pkgsettings[myroot]
                args = []
                onlydeps = "--onlydeps" in self.myopts
                lookup_owners = []
                for x in myfiles:
                        ext = os.path.splitext(x)[1]
                        if ext==".tbz2":
                                if not os.path.exists(x):
                                        if os.path.exists(
                                                os.path.join(pkgsettings["PKGDIR"], "All", x)):
                                                x = os.path.join(pkgsettings["PKGDIR"], "All", x)
                                        elif os.path.exists(
                                                os.path.join(pkgsettings["PKGDIR"], x)):
                                                x = os.path.join(pkgsettings["PKGDIR"], x)
                                        else:
                                                print "\n\n!!! Binary package '"+str(x)+"' does not exist."
                                                print "!!! Please ensure the tbz2 exists as specified.\n"
                                                return 0, myfavorites
                                mytbz2=portage.xpak.tbz2(x)
                                mykey=mytbz2.getelements("CATEGORY")[0]+"/"+os.path.splitext(os.path.basename(x))[0]
                                if os.path.realpath(x) != \
                                        os.path.realpath(self.trees[myroot]["bintree"].getname(mykey)):
                                        print colorize("BAD", "\n*** You need to adjust PKGDIR to emerge this package.\n")
                                        return 0, myfavorites
                                db_keys = list(bindb._aux_cache_keys)
                                metadata = izip(db_keys, bindb.aux_get(mykey, db_keys))
                                pkg = Package(type_name="binary", root_config=root_config,
                                        cpv=mykey, built=True, metadata=metadata,
                                        onlydeps=onlydeps)
                                self._pkg_cache[pkg] = pkg
                                args.append(PackageArg(arg=x, package=pkg,
                                        root_config=root_config))
                        elif ext==".ebuild":
                                ebuild_path = portage.util.normalize_path(os.path.abspath(x))
                                pkgdir = os.path.dirname(ebuild_path)
                                tree_root = os.path.dirname(os.path.dirname(pkgdir))
                                cp = pkgdir[len(tree_root)+1:]
                                e = portage.exception.PackageNotFound(
                                        ("%s is not in a valid portage tree " + \
                                        "hierarchy or does not exist") % x)
                                if not portage.isvalidatom(cp):
                                        raise e
                                cat = portage.catsplit(cp)[0]
                                mykey = cat + "/" + os.path.basename(ebuild_path[:-7])
                                if not portage.isvalidatom("="+mykey):
                                        raise e
                                ebuild_path = portdb.findname(mykey)
                                if ebuild_path:
                                        if ebuild_path != os.path.join(os.path.realpath(tree_root),
                                                cp, os.path.basename(ebuild_path)):
                                                print colorize("BAD", "\n*** You need to adjust PORTDIR or PORTDIR_OVERLAY to emerge this package.\n")
                                                return 0, myfavorites
                                        if mykey not in portdb.xmatch(
                                                "match-visible", portage.dep_getkey(mykey)):
                                                print colorize("BAD", "\n*** You are emerging a masked package. It is MUCH better to use")
                                                print colorize("BAD", "*** /etc/portage/package.* to accomplish this. See portage(5) man")
                                                print colorize("BAD", "*** page for details.")
                                                countdown(int(self.settings["EMERGE_WARNING_DELAY"]),
                                                        "Continuing...")
                                else:
                                        raise portage.exception.PackageNotFound(
                                                "%s is not in a valid portage tree hierarchy or does not exist" % x)
                                db_keys = list(portdb._aux_cache_keys)
                                metadata = izip(db_keys, portdb.aux_get(mykey, db_keys))
                                pkg = Package(type_name="ebuild", root_config=root_config,
                                        cpv=mykey, metadata=metadata, onlydeps=onlydeps)
                                pkgsettings.setcpv(pkg)
                                pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
                                self._pkg_cache[pkg] = pkg
                                args.append(PackageArg(arg=x, package=pkg,
                                        root_config=root_config))
                        elif x.startswith(os.path.sep):
                                if not x.startswith(myroot):
                                        portage.writemsg(("\n\n!!! '%s' does not start with" + \
                                                " $ROOT.\n") % x, noiselevel=-1)
                                        return 0, []
                                # Queue these up since it's most efficient to handle
                                # multiple files in a single iter_owners() call.
                                lookup_owners.append(x)
                        else:
                                if x in ("system", "world"):
                                        x = SETPREFIX + x
                                if x.startswith(SETPREFIX):
                                        s = x[len(SETPREFIX):]
                                        if s not in sets:
                                                raise portage.exception.PackageSetNotFound(s)
                                        if s in self._sets:
                                                continue
                                        # Recursively expand sets so that containment tests in
                                        # self._get_parent_sets() properly match atoms in nested
                                        # sets (like if world contains system).
                                        expanded_set = InternalPackageSet(
                                                initial_atoms=getSetAtoms(s))
                                        self._sets[s] = expanded_set
                                        args.append(SetArg(arg=x, set=expanded_set,
                                                root_config=root_config))
                                        myfavorites.append(x)
                                        continue
                                if not is_valid_package_atom(x):
                                        portage.writemsg("\n\n!!! '%s' is not a valid package atom.\n" % x,
                                                noiselevel=-1)
                                        portage.writemsg("!!! Please check ebuild(5) for full details.\n")
                                        portage.writemsg("!!! (Did you specify a version but forget to prefix with '='?)\n")
                                        return (0,[])
                                # Don't expand categories or old-style virtuals here unless
                                # necessary. Expansion of old-style virtuals here causes at
                                # least the following problems:
                                #   1) It's more difficult to determine which set(s) an atom
                                #      came from, if any.
                                #   2) It takes away freedom from the resolver to choose other
                                #      possible expansions when necessary.
                                if "/" in x:
                                        args.append(AtomArg(arg=x, atom=x,
                                                root_config=root_config))
                                        continue
                                expanded_atoms = self._dep_expand(root_config, x)
                                installed_cp_set = set()
                                for atom in expanded_atoms:
                                        atom_cp = portage.dep_getkey(atom)
                                        if vardb.cp_list(atom_cp):
                                                installed_cp_set.add(atom_cp)
                                if len(expanded_atoms) > 1 and len(installed_cp_set) == 1:
                                        installed_cp = iter(installed_cp_set).next()
                                        expanded_atoms = [atom for atom in expanded_atoms \
                                                if portage.dep_getkey(atom) == installed_cp]

                                if len(expanded_atoms) > 1:
                                        print
                                        print
                                        ambiguous_package_name(x, expanded_atoms, root_config,
                                                self.spinner, self.myopts)
                                        return False, myfavorites
                                if expanded_atoms:
                                        atom = expanded_atoms[0]
                                else:
                                        null_atom = insert_category_into_atom(x, "null")
                                        null_cp = portage.dep_getkey(null_atom)
                                        cat, atom_pn = portage.catsplit(null_cp)
                                        virts_p = root_config.settings.get_virts_p().get(atom_pn)
                                        if virts_p:
                                                # Allow the depgraph to choose which virtual.
                                                atom = insert_category_into_atom(x, "virtual")
                                        else:
                                                atom = insert_category_into_atom(x, "null")

                                args.append(AtomArg(arg=x, atom=atom,
                                        root_config=root_config))

                if lookup_owners:
                        relative_paths = []
                        search_for_multiple = False
                        if len(lookup_owners) > 1:
                                search_for_multiple = True

                        for x in lookup_owners:
                                if not search_for_multiple and os.path.isdir(x):
                                        search_for_multiple = True
                                relative_paths.append(x[len(myroot):])

                        owners = set()
                        for pkg, relative_path in \
                                real_vardb._owners.iter_owners(relative_paths):
                                owners.add(pkg.mycpv)
                                if not search_for_multiple:
                                        break

                        if not owners:
                                portage.writemsg(("\n\n!!! '%s' is not claimed " + \
                                        "by any package.\n") % lookup_owners[0], noiselevel=-1)
                                return 0, []

                        for cpv in owners:
                                slot = vardb.aux_get(cpv, ["SLOT"])[0]
                                if not slot:
                                        # portage now masks packages with missing slot, but it's
                                        # possible that one was installed by an older version
                                        atom = portage.cpv_getkey(cpv)
                                else:
                                        atom = "%s:%s" % (portage.cpv_getkey(cpv), slot)
                                args.append(AtomArg(arg=atom, atom=atom,
                                        root_config=root_config))

                if "--update" in self.myopts:
                        # Enable greedy SLOT atoms for atoms given as arguments.
                        # This is currently disabled for sets since greedy SLOT
                        # atoms could be a property of the set itself.
                        greedy_atoms = []
                        for arg in args:
                                # In addition to any installed slots, also try to pull
                                # in the latest new slot that may be available.
                                greedy_atoms.append(arg)
                                if not isinstance(arg, (AtomArg, PackageArg)):
                                        continue
                                atom_cp = portage.dep_getkey(arg.atom)
                                slots = set()
                                for cpv in vardb.match(arg.atom):
                                        slots.add(vardb.aux_get(cpv, ["SLOT"])[0])
                                for slot in slots:
                                        greedy_atoms.append(
                                                AtomArg(arg=arg.arg, atom="%s:%s" % (atom_cp, slot),
                                                        root_config=root_config))
                        args = greedy_atoms
                        del greedy_atoms

                # Create the "args" package set from atoms and
                # packages given as arguments.
                args_set = self._sets["args"]
                for arg in args:
                        if not isinstance(arg, (AtomArg, PackageArg)):
                                continue
                        myatom = arg.atom
                        if myatom in args_set:
                                continue
                        args_set.add(myatom)
                        myfavorites.append(myatom)
                self._set_atoms.update(chain(*self._sets.itervalues()))
                atom_arg_map = self._atom_arg_map
                for arg in args:
                        for atom in arg.set:
                                atom_key = (atom, myroot)
                                refs = atom_arg_map.get(atom_key)
                                if refs is None:
                                        refs = []
                                        atom_arg_map[atom_key] = refs
                                        if arg not in refs:
                                                refs.append(arg)
                pprovideddict = pkgsettings.pprovideddict
                if debug:
                        portage.writemsg("\n", noiselevel=-1)
                # Order needs to be preserved since a feature of --nodeps
                # is to allow the user to force a specific merge order.
                args.reverse()
                while args:
                        arg = args.pop()
                        for atom in arg.set:
                                self.spinner.update()
                                dep = Dependency(atom=atom, onlydeps=onlydeps,
                                        root=myroot, parent=arg)
                                atom_cp = portage.dep_getkey(atom)
                                try:
                                        pprovided = pprovideddict.get(portage.dep_getkey(atom))
                                        if pprovided and portage.match_from_list(atom, pprovided):
                                                # A provided package has been specified on the command line.
                                                self._pprovided_args.append((arg, atom))
                                                continue
                                        if isinstance(arg, PackageArg):
                                                if not self._add_pkg(arg.package, dep) or \
                                                        not self._create_graph():
                                                        sys.stderr.write(("\n\n!!! Problem resolving " + \
                                                                "dependencies for %s\n") % arg.arg)
                                                        return 0, myfavorites
                                                continue
                                        if debug:
                                                portage.writemsg("      Arg: %s\n     Atom: %s\n" % \
                                                        (arg, atom), noiselevel=-1)
                                        pkg, existing_node = self._select_package(
                                                myroot, atom, onlydeps=onlydeps)
                                        if not pkg:
                                                if not (isinstance(arg, SetArg) and \
                                                        arg.name in ("system", "world")):
                                                        self._unsatisfied_deps_for_display.append(
                                                                ((myroot, atom), {}))
                                                        return 0, myfavorites
                                                self._missing_args.append((arg, atom))
                                                continue
                                        if atom_cp != pkg.cp:
                                                # For old-style virtuals, we need to repeat the
                                                # package.provided check against the selected package.
                                                expanded_atom = atom.replace(atom_cp, pkg.cp)
                                                pprovided = pprovideddict.get(pkg.cp)
                                                if pprovided and \
                                                        portage.match_from_list(expanded_atom, pprovided):
                                                        # A provided package has been
                                                        # specified on the command line.
                                                        self._pprovided_args.append((arg, atom))
                                                        continue
                                        if pkg.installed and "selective" not in self.myparams:
                                                self._unsatisfied_deps_for_display.append(
                                                        ((myroot, atom), {}))
                                                # Previous behavior was to bail out in this case, but
                                                # since the dep is satisfied by the installed package,
                                                # it's more friendly to continue building the graph
                                                # and just show a warning message. Therefore, only bail
                                                # out here if the atom is not from either the system or
                                                # world set.
                                                if not (isinstance(arg, SetArg) and \
                                                        arg.name in ("system", "world")):
                                                        return 0, myfavorites

                                        # Add the selected package to the graph as soon as possible
                                        # so that later dep_check() calls can use it as feedback
                                        # for making more consistent atom selections.
                                        if not self._add_pkg(pkg, dep):
                                                if isinstance(arg, SetArg):
                                                        sys.stderr.write(("\n\n!!! Problem resolving " + \
                                                                "dependencies for %s from %s\n") % \
                                                                (atom, arg.arg))
                                                else:
                                                        sys.stderr.write(("\n\n!!! Problem resolving " + \
                                                                "dependencies for %s\n") % atom)
                                                return 0, myfavorites

                                except portage.exception.MissingSignature, e:
                                        portage.writemsg("\n\n!!! A missing gpg signature is preventing portage from calculating the\n")
                                        portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
                                        portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
                                        portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
                                        portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
                                        return 0, myfavorites
                                except portage.exception.InvalidSignature, e:
                                        portage.writemsg("\n\n!!! An invalid gpg signature is preventing portage from calculating the\n")
                                        portage.writemsg("!!! required dependencies. This is a security feature enabled by the admin\n")
                                        portage.writemsg("!!! to aid in the detection of malicious intent.\n\n")
                                        portage.writemsg("!!! THIS IS A POSSIBLE INDICATION OF TAMPERED FILES -- CHECK CAREFULLY.\n")
                                        portage.writemsg("!!! Affected file: %s\n" % (e), noiselevel=-1)
                                        return 0, myfavorites
                                except SystemExit, e:
                                        raise # Needed else can't exit
                                except Exception, e:
                                        print >> sys.stderr, "\n\n!!! Problem in '%s' dependencies." % atom
                                        print >> sys.stderr, "!!!", str(e), getattr(e, "__module__", None)
                                        raise

                # Now that the root packages have been added to the graph,
                # process the dependencies.
                if not self._create_graph():
                        return 0, myfavorites

                missing=0
                if "--usepkgonly" in self.myopts:
                        for xs in self.digraph.all_nodes():
                                if not isinstance(xs, Package):
                                        continue
                                if len(xs) >= 4 and xs[0] != "binary" and xs[3] == "merge":
                                        if missing == 0:
                                                print
                                        missing += 1
                                        print "Missing binary for:",xs[2]

                try:
                        self.altlist()
                except self._unknown_internal_error:
                        return False, myfavorites

                # We're true here unless we are missing binaries.
                return (not missing,myfavorites)

        def _select_atoms_from_graph(self, *pargs, **kwargs):
                """
                Prefer atoms matching packages that have already been
                added to the graph or those that are installed and have
                not been scheduled for replacement.
                """
                kwargs["trees"] = self._graph_trees
                return self._select_atoms_highest_available(*pargs, **kwargs)

        def _select_atoms_highest_available(self, root, depstring,
                myuse=None, parent=None, strict=True, trees=None):
                """This will raise InvalidDependString if necessary. If trees is
                None then self._filtered_trees is used."""
                pkgsettings = self.pkgsettings[root]
                if trees is None:
                        trees = self._filtered_trees
                if True:
                        try:
                                if parent is not None:
                                        trees[root]["parent"] = parent
                                if not strict:
                                        portage.dep._dep_check_strict = False
                                mycheck = portage.dep_check(depstring, None,
                                        pkgsettings, myuse=myuse,
                                        myroot=root, trees=trees)
                        finally:
                                if parent is not None:
                                        trees[root].pop("parent")
                                portage.dep._dep_check_strict = True
                        if not mycheck[0]:
                                raise portage.exception.InvalidDependString(mycheck[1])
                        selected_atoms = mycheck[1]
                return selected_atoms

        def _show_unsatisfied_dep(self, root, atom, myparent=None, arg=None):
                atom = portage.dep.Atom(atom)
                atom_set = InternalPackageSet(initial_atoms=(atom,))
                atom_without_use = atom
                if atom.use:
                        atom_without_use = portage.dep.remove_slot(atom)
                        if atom.slot:
                                atom_without_use += ":" + atom.slot
                        atom_without_use = portage.dep.Atom(atom_without_use)
                xinfo = '"%s"' % atom
                if arg:
                        xinfo='"%s"' % arg
                # Discard null/ from failed cpv_expand category expansion.
                xinfo = xinfo.replace("null/", "")
                masked_packages = []
                missing_use = []
                missing_licenses = []
                have_eapi_mask = False
                pkgsettings = self.pkgsettings[root]
                implicit_iuse = pkgsettings._get_implicit_iuse()
                root_config = self.roots[root]
                portdb = self.roots[root].trees["porttree"].dbapi
                dbs = self._filtered_trees[root]["dbs"]
                for db, pkg_type, built, installed, db_keys in dbs:
                        if installed:
                                continue
                        match = db.match
                        if hasattr(db, "xmatch"):
                                cpv_list = db.xmatch("match-all", atom_without_use)
                        else:
                                cpv_list = db.match(atom_without_use)
                        # descending order
                        cpv_list.reverse()
                        for cpv in cpv_list:
                                metadata, mreasons  = get_mask_info(root_config, cpv,
                                        pkgsettings, db, pkg_type, built, installed, db_keys)
                                if metadata is not None:
                                        pkg = Package(built=built, cpv=cpv,
                                                installed=installed, metadata=metadata,
                                                root_config=root_config)
                                        if pkg.cp != atom.cp:
                                                # A cpv can be returned from dbapi.match() as an
                                                # old-style virtual match even in cases when the
                                                # package does not actually PROVIDE the virtual.
                                                # Filter out any such false matches here.
                                                if not atom_set.findAtomForPackage(pkg):
                                                        continue
                                        if atom.use and not mreasons:
                                                missing_use.append(pkg)
                                                continue
                                masked_packages.append(
                                        (root_config, pkgsettings, cpv, metadata, mreasons))

                missing_use_reasons = []
                missing_iuse_reasons = []
                for pkg in missing_use:
                        use = pkg.use.enabled
                        iuse = implicit_iuse.union(re.escape(x) for x in pkg.iuse.all)
                        iuse_re = re.compile("^(%s)$" % "|".join(iuse))
                        missing_iuse = []
                        for x in atom.use.required:
                                if iuse_re.match(x) is None:
                                        missing_iuse.append(x)
                        mreasons = []
                        if missing_iuse:
                                mreasons.append("Missing IUSE: %s" % " ".join(missing_iuse))
                                missing_iuse_reasons.append((pkg, mreasons))
                        else:
                                need_enable = sorted(atom.use.enabled.difference(use))
                                need_disable = sorted(atom.use.disabled.intersection(use))
                                if need_enable or need_disable:
                                        changes = []
                                        changes.extend(colorize("red", "+" + x) \
                                                for x in need_enable)
                                        changes.extend(colorize("blue", "-" + x) \
                                                for x in need_disable)
                                        mreasons.append("Change USE: %s" % " ".join(changes))
                                        missing_use_reasons.append((pkg, mreasons))

                if missing_iuse_reasons and not missing_use_reasons:
                        missing_use_reasons = missing_iuse_reasons
                elif missing_use_reasons:
                        # Only show the latest version.
                        del missing_use_reasons[1:]

                if missing_use_reasons:
                        print "\nemerge: there are no ebuilds built with USE flags to satisfy "+green(xinfo)+"."
                        print "!!! One of the following packages is required to complete your request:"
                        for pkg, mreasons in missing_use_reasons:
                                print "- "+pkg.cpv+" ("+", ".join(mreasons)+")"

                elif masked_packages:
                        print "\n!!! " + \
                                colorize("BAD", "All ebuilds that could satisfy ") + \
                                colorize("INFORM", xinfo) + \
                                colorize("BAD", " have been masked.")
                        print "!!! One of the following masked packages is required to complete your request:"
                        have_eapi_mask = show_masked_packages(masked_packages)
                        if have_eapi_mask:
                                print
                                msg = ("The current version of portage supports " + \
                                        "EAPI '%s'. You must upgrade to a newer version" + \
                                        " of portage before EAPI masked packages can" + \
                                        " be installed.") % portage.const.EAPI
                                from textwrap import wrap
                                for line in wrap(msg, 75):
                                        print line
                        print
                        show_mask_docs()
                else:
                        print "\nemerge: there are no ebuilds to satisfy "+green(xinfo)+"."

                # Show parent nodes and the argument that pulled them in.
                traversed_nodes = set()
                node = myparent
                msg = []
                while node is not None:
                        traversed_nodes.add(node)
                        msg.append('(dependency required by "%s" [%s])' % \
                                (colorize('INFORM', str(node.cpv)), node.type_name))
                        # When traversing to parents, prefer arguments over packages
                        # since arguments are root nodes. Never traverse the same
                        # package twice, in order to prevent an infinite loop.
                        selected_parent = None
                        for parent in self.digraph.parent_nodes(node):
                                if isinstance(parent, DependencyArg):
                                        msg.append('(dependency required by "%s" [argument])' % \
                                                (colorize('INFORM', str(parent))))
                                        selected_parent = None
                                        break
                                if parent not in traversed_nodes:
                                        selected_parent = parent
                        node = selected_parent
                for line in msg:
                        print line

                print

        def _select_pkg_highest_available(self, root, atom, onlydeps=False):
                cache_key = (root, atom, onlydeps)
                ret = self._highest_pkg_cache.get(cache_key)
                if ret is not None:
                        pkg, existing = ret
                        if pkg and not existing:
                                existing = self._slot_pkg_map[root].get(pkg.slot_atom)
                                if existing and existing == pkg:
                                        # Update the cache to reflect that the
                                        # package has been added to the graph.
                                        ret = pkg, pkg
                                        self._highest_pkg_cache[cache_key] = ret
                        return ret
                ret = self._select_pkg_highest_available_imp(root, atom, onlydeps=onlydeps)
                self._highest_pkg_cache[cache_key] = ret
                return ret

        def _select_pkg_highest_available_imp(self, root, atom, onlydeps=False):
                root_config = self.roots[root]
                pkgsettings = self.pkgsettings[root]
                dbs = self._filtered_trees[root]["dbs"]
                vardb = self.roots[root].trees["vartree"].dbapi
                portdb = self.roots[root].trees["porttree"].dbapi
                # List of acceptable packages, ordered by type preference.
                matched_packages = []
                highest_version = None
                if not isinstance(atom, portage.dep.Atom):
                        atom = portage.dep.Atom(atom)
                atom_cp = atom.cp
                atom_set = InternalPackageSet(initial_atoms=(atom,))
                existing_node = None
                myeb = None
                usepkgonly = "--usepkgonly" in self.myopts
                empty = "empty" in self.myparams
                selective = "selective" in self.myparams
                reinstall = False
                noreplace = "--noreplace" in self.myopts
                # Behavior of the "selective" parameter depends on
                # whether or not a package matches an argument atom.
                # If an installed package provides an old-style
                # virtual that is no longer provided by an available
                # package, the installed package may match an argument
                # atom even though none of the available packages do.
                # Therefore, "selective" logic does not consider
                # whether or not an installed package matches an
                # argument atom. It only considers whether or not
                # available packages match argument atoms, which is
                # represented by the found_available_arg flag.
                found_available_arg = False
                for find_existing_node in True, False:
                        if existing_node:
                                break
                        for db, pkg_type, built, installed, db_keys in dbs:
                                if existing_node:
                                        break
                                if installed and not find_existing_node:
                                        want_reinstall = reinstall or empty or \
                                                (found_available_arg and not selective)
                                        if want_reinstall and matched_packages:
                                                continue
                                if hasattr(db, "xmatch"):
                                        cpv_list = db.xmatch("match-all", atom)
                                else:
                                        cpv_list = db.match(atom)

                                # USE=multislot can make an installed package appear as if
                                # it doesn't satisfy a slot dependency. Rebuilding the ebuild
                                # won't do any good as long as USE=multislot is enabled since
                                # the newly built package still won't have the expected slot.
                                # Therefore, assume that such SLOT dependencies are already
                                # satisfied rather than forcing a rebuild.
                                if installed and not cpv_list and atom.slot:
                                        for cpv in db.match(atom.cp):
                                                slot_available = False
                                                for other_db, other_type, other_built, \
                                                        other_installed, other_keys in dbs:
                                                        try:
                                                                if atom.slot == \
                                                                        other_db.aux_get(cpv, ["SLOT"])[0]:
                                                                        slot_available = True
                                                                        break
                                                        except KeyError:
                                                                pass
                                                if not slot_available:
                                                        continue
                                                inst_pkg = self._pkg(cpv, "installed",
                                                        root_config, installed=installed)
                                                # Remove the slot from the atom and verify that
                                                # the package matches the resulting atom.
                                                atom_without_slot = portage.dep.remove_slot(atom)
                                                if atom.use:
                                                        atom_without_slot += str(atom.use)
                                                atom_without_slot = portage.dep.Atom(atom_without_slot)
                                                if portage.match_from_list(
                                                        atom_without_slot, [inst_pkg]):
                                                        cpv_list = [inst_pkg.cpv]
                                                break

                                if not cpv_list:
                                        continue
                                pkg_status = "merge"
                                if installed or onlydeps:
                                        pkg_status = "nomerge"
                                # descending order
                                cpv_list.reverse()
                                for cpv in cpv_list:
                                        # Make --noreplace take precedence over --newuse.
                                        if not installed and noreplace and \
                                                cpv in vardb.match(atom):
                                                # If the installed version is masked, it may
                                                # be necessary to look at lower versions,
                                                # in case there is a visible downgrade.
                                                continue
                                        reinstall_for_flags = None
                                        cache_key = (pkg_type, root, cpv, pkg_status)
                                        calculated_use = True
                                        pkg = self._pkg_cache.get(cache_key)
                                        if pkg is None:
                                                calculated_use = False
                                                try:
                                                        metadata = izip(db_keys, db.aux_get(cpv, db_keys))
                                                except KeyError:
                                                        continue
                                                pkg = Package(built=built, cpv=cpv,
                                                        installed=installed, metadata=metadata,
                                                        onlydeps=onlydeps, root_config=root_config,
                                                        type_name=pkg_type)
                                                metadata = pkg.metadata
                                                if not built and ("?" in metadata["LICENSE"] or \
                                                        "?" in metadata["PROVIDE"]):
                                                        # This is avoided whenever possible because
                                                        # it's expensive. It only needs to be done here
                                                        # if it has an effect on visibility.
                                                        pkgsettings.setcpv(pkg)
                                                        metadata["USE"] = pkgsettings["PORTAGE_USE"]
                                                        calculated_use = True
                                                self._pkg_cache[pkg] = pkg

                                        if not installed or (installed and matched_packages):
                                                # Only enforce visibility on installed packages
                                                # if there is at least one other visible package
                                                # available. By filtering installed masked packages
                                                # here, packages that have been masked since they
                                                # were installed can be automatically downgraded
                                                # to an unmasked version.
                                                try:
                                                        if not visible(pkgsettings, pkg):
                                                                continue
                                                except portage.exception.InvalidDependString:
                                                        if not installed:
                                                                continue

                                                # Enable upgrade or downgrade to a version
                                                # with visible KEYWORDS when the installed
                                                # version is masked by KEYWORDS, but never
                                                # reinstall the same exact version only due
                                                # to a KEYWORDS mask.
                                                if installed and matched_packages and \
                                                        pkgsettings._getMissingKeywords(
                                                        pkg.cpv, pkg.metadata):
                                                        different_version = None
                                                        for avail_pkg in matched_packages:
                                                                if not portage.dep.cpvequal(
                                                                        pkg.cpv, avail_pkg.cpv):
                                                                        different_version = avail_pkg
                                                                        break
                                                        if different_version is not None:
                                                                # Only reinstall for KEYWORDS if
                                                                # it's not the same version.
                                                                continue

                                        if not pkg.built and not calculated_use:
                                                # This is avoided whenever possible because
                                                # it's expensive.
                                                pkgsettings.setcpv(pkg)
                                                pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]

                                        if pkg.cp != atom.cp:
                                                # A cpv can be returned from dbapi.match() as an
                                                # old-style virtual match even in cases when the
                                                # package does not actually PROVIDE the virtual.
                                                # Filter out any such false matches here.
                                                if not atom_set.findAtomForPackage(pkg):
                                                        continue

                                        myarg = None
                                        if root == self.target_root:
                                                try:
                                                        # Ebuild USE must have been calculated prior
                                                        # to this point, in case atoms have USE deps.
                                                        myarg = self._iter_atoms_for_pkg(pkg).next()
                                                except StopIteration:
                                                        pass
                                                except portage.exception.InvalidDependString:
                                                        if not installed:
                                                                # masked by corruption
                                                                continue
                                        if not installed and myarg:
                                                found_available_arg = True

                                        if atom.use and not pkg.built:
                                                use = pkg.use.enabled
                                                if atom.use.enabled.difference(use):
                                                        continue
                                                if atom.use.disabled.intersection(use):
                                                        continue
                                        if pkg.cp == atom_cp:
                                                if highest_version is None:
                                                        highest_version = pkg
                                                elif pkg > highest_version:
                                                        highest_version = pkg
                                        # At this point, we've found the highest visible
                                        # match from the current repo. Any lower versions
                                        # from this repo are ignored, so this so the loop
                                        # will always end with a break statement below
                                        # this point.
                                        if find_existing_node:
                                                e_pkg = self._slot_pkg_map[root].get(pkg.slot_atom)
                                                if not e_pkg:
                                                        break
                                                if portage.dep.match_from_list(atom, [e_pkg]):
                                                        if highest_version and \
                                                                e_pkg.cp == atom_cp and \
                                                                e_pkg < highest_version and \
                                                                e_pkg.slot_atom != highest_version.slot_atom:
                                                                # There is a higher version available in a
                                                                # different slot, so this existing node is
                                                                # irrelevant.
                                                                pass
                                                        else:
                                                                matched_packages.append(e_pkg)
                                                                existing_node = e_pkg
                                                break
                                        # Compare built package to current config and
                                        # reject the built package if necessary.
                                        if built and not installed and \
                                                ("--newuse" in self.myopts or \
                                                "--reinstall" in self.myopts):
                                                iuses = pkg.iuse.all
                                                old_use = pkg.use.enabled
                                                if myeb:
                                                        pkgsettings.setcpv(myeb)
                                                else:
                                                        pkgsettings.setcpv(pkg)
                                                now_use = pkgsettings["PORTAGE_USE"].split()
                                                forced_flags = set()
                                                forced_flags.update(pkgsettings.useforce)
                                                forced_flags.update(pkgsettings.usemask)
                                                cur_iuse = iuses
                                                if myeb and not usepkgonly:
                                                        cur_iuse = myeb.iuse.all
                                                if self._reinstall_for_flags(forced_flags,
                                                        old_use, iuses,
                                                        now_use, cur_iuse):
                                                        break
                                        # Compare current config to installed package
                                        # and do not reinstall if possible.
                                        if not installed and \
                                                ("--newuse" in self.myopts or \
                                                "--reinstall" in self.myopts) and \
                                                cpv in vardb.match(atom):
                                                pkgsettings.setcpv(pkg)
                                                forced_flags = set()
                                                forced_flags.update(pkgsettings.useforce)
                                                forced_flags.update(pkgsettings.usemask)
                                                old_use = vardb.aux_get(cpv, ["USE"])[0].split()
                                                old_iuse = set(filter_iuse_defaults(
                                                        vardb.aux_get(cpv, ["IUSE"])[0].split()))
                                                cur_use = pkgsettings["PORTAGE_USE"].split()
                                                cur_iuse = pkg.iuse.all
                                                reinstall_for_flags = \
                                                        self._reinstall_for_flags(
                                                        forced_flags, old_use, old_iuse,
                                                        cur_use, cur_iuse)
                                                if reinstall_for_flags:
                                                        reinstall = True
                                        if not built:
                                                myeb = pkg
                                        matched_packages.append(pkg)
                                        if reinstall_for_flags:
                                                self._reinstall_nodes[pkg] = \
                                                        reinstall_for_flags
                                        break

                if not matched_packages:
                        return None, None

                if "--debug" in self.myopts:
                        for pkg in matched_packages:
                                portage.writemsg("%s %s\n" % \
                                        ((pkg.type_name + ":").rjust(10), pkg.cpv), noiselevel=-1)

                # Filter out any old-style virtual matches if they are
                # mixed with new-style virtual matches.
                cp = portage.dep_getkey(atom)
                if len(matched_packages) > 1 and \
                        "virtual" == portage.catsplit(cp)[0]:
                        for pkg in matched_packages:
                                if pkg.cp != cp:
                                        continue
                                # Got a new-style virtual, so filter
                                # out any old-style virtuals.
                                matched_packages = [pkg for pkg in matched_packages \
                                        if pkg.cp == cp]
                                break

                # If the installed version is in a different slot and it is higher than
                # the highest available visible package, _iter_atoms_for_pkg() may fail
                # to properly match the available package with a corresponding argument
                # atom. Detect this case and correct it here.
                if not selective and len(matched_packages) > 1 and \
                        matched_packages[-1].installed and \
                        matched_packages[-1].slot_atom != \
                        matched_packages[-2].slot_atom and \
                        matched_packages[-1] > matched_packages[-2]:
                        pkg = matched_packages[-2]
                        if pkg.root == self.target_root and \
                                self._set_atoms.findAtomForPackage(pkg):
                                # Select the available package instead
                                # of the installed package.
                                matched_packages.pop()

                if len(matched_packages) > 1:
                        bestmatch = portage.best(
                                [pkg.cpv for pkg in matched_packages])
                        matched_packages = [pkg for pkg in matched_packages \
                                if portage.dep.cpvequal(pkg.cpv, bestmatch)]

                # ordered by type preference ("ebuild" type is the last resort)
                return  matched_packages[-1], existing_node

        def _select_pkg_from_graph(self, root, atom, onlydeps=False):
                """
                Select packages that have already been added to the graph or
                those that are installed and have not been scheduled for
                replacement.
                """
                graph_db = self._graph_trees[root]["porttree"].dbapi
                matches = graph_db.match(atom)
                if not matches:
                        return None, None
                cpv = matches[-1] # highest match
                slot_atom = "%s:%s" % (portage.cpv_getkey(cpv),
                        graph_db.aux_get(cpv, ["SLOT"])[0])
                e_pkg = self._slot_pkg_map[root].get(slot_atom)
                if e_pkg:
                        return e_pkg, e_pkg
                # Since this cpv exists in the graph_db,
                # we must have a cached Package instance.
                cache_key = ("installed", root, cpv, "nomerge")
                return (self._pkg_cache[cache_key], None)

        def _complete_graph(self):
                """
                Add any deep dependencies of required sets (args, system, world) that
                have not been pulled into the graph yet. This ensures that the graph
                is consistent such that initially satisfied deep dependencies are not
                broken in the new graph. Initially unsatisfied dependencies are
                irrelevant since we only want to avoid breaking dependencies that are
                intially satisfied.

                Since this method can consume enough time to disturb users, it is
                currently only enabled by the --complete-graph option.
                """
                if "--buildpkgonly" in self.myopts or \
                        "recurse" not in self.myparams:
                        return 1

                if "complete" not in self.myparams:
                        # Skip this to avoid consuming enough time to disturb users.
                        return 1

                # Put the depgraph into a mode that causes it to only
                # select packages that have already been added to the
                # graph or those that are installed and have not been
                # scheduled for replacement. Also, toggle the "deep"
                # parameter so that all dependencies are traversed and
                # accounted for.
                self._select_atoms = self._select_atoms_from_graph
                self._select_package = self._select_pkg_from_graph
                already_deep = "deep" in self.myparams
                if not already_deep:
                        self.myparams.add("deep")

                for root in self.roots:
                        required_set_names = self._required_set_names.copy()
                        if root == self.target_root and \
                                (already_deep or "empty" in self.myparams):
                                required_set_names.difference_update(self._sets)
                        if not required_set_names and not self._ignored_deps:
                                continue
                        root_config = self.roots[root]
                        setconfig = root_config.setconfig
                        args = []
                        # Reuse existing SetArg instances when available.
                        for arg in self.digraph.root_nodes():
                                if not isinstance(arg, SetArg):
                                        continue
                                if arg.root_config != root_config:
                                        continue
                                if arg.name in required_set_names:
                                        args.append(arg)
                                        required_set_names.remove(arg.name)
                        # Create new SetArg instances only when necessary.
                        for s in required_set_names:
                                expanded_set = InternalPackageSet(
                                        initial_atoms=setconfig.getSetAtoms(s))
                                atom = SETPREFIX + s
                                args.append(SetArg(arg=atom, set=expanded_set,
                                        root_config=root_config))
                        vardb = root_config.trees["vartree"].dbapi
                        for arg in args:
                                for atom in arg.set:
                                        self._dep_stack.append(
                                                Dependency(atom=atom, root=root, parent=arg))
                        if self._ignored_deps:
                                self._dep_stack.extend(self._ignored_deps)
                                self._ignored_deps = []
                        if not self._create_graph(allow_unsatisfied=True):
                                return 0
                        # Check the unsatisfied deps to see if any initially satisfied deps
                        # will become unsatisfied due to an upgrade. Initially unsatisfied
                        # deps are irrelevant since we only want to avoid breaking deps
                        # that are initially satisfied.
                        while self._unsatisfied_deps:
                                dep = self._unsatisfied_deps.pop()
                                matches = vardb.match_pkgs(dep.atom)
                                if not matches:
                                        self._initially_unsatisfied_deps.append(dep)
                                        continue
                                # An scheduled installation broke a deep dependency.
                                # Add the installed package to the graph so that it
                                # will be appropriately reported as a slot collision
                                # (possibly solvable via backtracking).
                                pkg = matches[-1] # highest match
                                if not self._add_pkg(pkg, dep):
                                        return 0
                                if not self._create_graph(allow_unsatisfied=True):
                                        return 0
                return 1

        def _pkg(self, cpv, type_name, root_config, installed=False):
                """
                Get a package instance from the cache, or create a new
                one if necessary. Raises KeyError from aux_get if it
                failures for some reason (package does not exist or is
                corrupt).
                """
                operation = "merge"
                if installed:
                        operation = "nomerge"
                pkg = self._pkg_cache.get(
                        (type_name, root_config.root, cpv, operation))
                if pkg is None:
                        tree_type = self.pkg_tree_map[type_name]
                        db = root_config.trees[tree_type].dbapi
                        db_keys = list(self._trees_orig[root_config.root][
                                tree_type].dbapi._aux_cache_keys)
                        metadata = izip(db_keys, db.aux_get(cpv, db_keys))
                        pkg = Package(cpv=cpv, metadata=metadata,
                                root_config=root_config, installed=installed)
                        if type_name == "ebuild":
                                settings = self.pkgsettings[root_config.root]
                                settings.setcpv(pkg)
                                pkg.metadata["USE"] = settings["PORTAGE_USE"]
                        self._pkg_cache[pkg] = pkg
                return pkg

        def validate_blockers(self):
                """Remove any blockers from the digraph that do not match any of the
                packages within the graph.  If necessary, create hard deps to ensure
                correct merge order such that mutually blocking packages are never
                installed simultaneously."""

                if "--buildpkgonly" in self.myopts or \
                        "--nodeps" in self.myopts:
                        return True

                #if "deep" in self.myparams:
                if True:
                        # Pull in blockers from all installed packages that haven't already
                        # been pulled into the depgraph.  This is not enabled by default
                        # due to the performance penalty that is incurred by all the
                        # additional dep_check calls that are required.

                        dep_keys = ["DEPEND","RDEPEND","PDEPEND"]
                        for myroot in self.trees:
                                vardb = self.trees[myroot]["vartree"].dbapi
                                portdb = self.trees[myroot]["porttree"].dbapi
                                pkgsettings = self.pkgsettings[myroot]
                                final_db = self.mydbapi[myroot]

                                blocker_cache = BlockerCache(myroot, vardb)
                                stale_cache = set(blocker_cache)
                                for pkg in vardb:
                                        cpv = pkg.cpv
                                        stale_cache.discard(cpv)
                                        pkg_in_graph = self.digraph.contains(pkg)

                                        # Check for masked installed packages. Only warn about
                                        # packages that are in the graph in order to avoid warning
                                        # about those that will be automatically uninstalled during
                                        # the merge process or by --depclean.
                                        if pkg in final_db:
                                                if pkg_in_graph and not visible(pkgsettings, pkg):
                                                        self._masked_installed.add(pkg)

                                        blocker_atoms = None
                                        blockers = None
                                        if pkg_in_graph:
                                                blockers = []
                                                try:
                                                        blockers.extend(
                                                                self._blocker_parents.child_nodes(pkg))
                                                except KeyError:
                                                        pass
                                                try:
                                                        blockers.extend(
                                                                self._irrelevant_blockers.child_nodes(pkg))
                                                except KeyError:
                                                        pass
                                        if blockers is not None:
                                                blockers = set(str(blocker.atom) \
                                                        for blocker in blockers)

                                        # If this node has any blockers, create a "nomerge"
                                        # node for it so that they can be enforced.
                                        self.spinner.update()
                                        blocker_data = blocker_cache.get(cpv)
                                        if blocker_data is not None and \
                                                blocker_data.counter != long(pkg.metadata["COUNTER"]):
                                                blocker_data = None

                                        # If blocker data from the graph is available, use
                                        # it to validate the cache and update the cache if
                                        # it seems invalid.
                                        if blocker_data is not None and \
                                                blockers is not None:
                                                if not blockers.symmetric_difference(
                                                        blocker_data.atoms):
                                                        continue
                                                blocker_data = None

                                        if blocker_data is None and \
                                                blockers is not None:
                                                # Re-use the blockers from the graph.
                                                blocker_atoms = sorted(blockers)
                                                counter = long(pkg.metadata["COUNTER"])
                                                blocker_data = \
                                                        blocker_cache.BlockerData(counter, blocker_atoms)
                                                blocker_cache[pkg.cpv] = blocker_data
                                                continue

                                        if blocker_data:
                                                blocker_atoms = blocker_data.atoms
                                        else:
                                                # Use aux_get() to trigger FakeVartree global
                                                # updates on *DEPEND when appropriate.
                                                depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
                                                # It is crucial to pass in final_db here in order to
                                                # optimize dep_check calls by eliminating atoms via
                                                # dep_wordreduce and dep_eval calls.
                                                try:
                                                        portage.dep._dep_check_strict = False
                                                        try:
                                                                success, atoms = portage.dep_check(depstr,
                                                                        final_db, pkgsettings, myuse=pkg.use.enabled,
                                                                        trees=self._graph_trees, myroot=myroot)
                                                        except Exception, e:
                                                                if isinstance(e, SystemExit):
                                                                        raise
                                                                # This is helpful, for example, if a ValueError
                                                                # is thrown from cpv_expand due to multiple
                                                                # matches (this can happen if an atom lacks a
                                                                # category).
                                                                show_invalid_depstring_notice(
                                                                        pkg, depstr, str(e))
                                                                del e
                                                                raise
                                                finally:
                                                        portage.dep._dep_check_strict = True
                                                if not success:
                                                        replacement_pkg = final_db.match_pkgs(pkg.slot_atom)
                                                        if replacement_pkg and \
                                                                replacement_pkg[0].operation == "merge":
                                                                # This package is being replaced anyway, so
                                                                # ignore invalid dependencies so as not to
                                                                # annoy the user too much (otherwise they'd be
                                                                # forced to manually unmerge it first).
                                                                continue
                                                        show_invalid_depstring_notice(pkg, depstr, atoms)
                                                        return False
                                                blocker_atoms = [myatom for myatom in atoms \
                                                        if myatom.startswith("!")]
                                                blocker_atoms.sort()
                                                counter = long(pkg.metadata["COUNTER"])
                                                blocker_cache[cpv] = \
                                                        blocker_cache.BlockerData(counter, blocker_atoms)
                                        if blocker_atoms:
                                                try:
                                                        for atom in blocker_atoms:
                                                                blocker = Blocker(atom=portage.dep.Atom(atom),
                                                                        eapi=pkg.metadata["EAPI"], root=myroot)
                                                                self._blocker_parents.add(blocker, pkg)
                                                except portage.exception.InvalidAtom, e:
                                                        depstr = " ".join(vardb.aux_get(pkg.cpv, dep_keys))
                                                        show_invalid_depstring_notice(
                                                                pkg, depstr, "Invalid Atom: %s" % (e,))
                                                        return False
                                for cpv in stale_cache:
                                        del blocker_cache[cpv]
                                blocker_cache.flush()
                                del blocker_cache

                # Discard any "uninstall" tasks scheduled by previous calls
                # to this method, since those tasks may not make sense given
                # the current graph state.
                previous_uninstall_tasks = self._blocker_uninstalls.leaf_nodes()
                if previous_uninstall_tasks:
                        self._blocker_uninstalls = digraph()
                        self.digraph.difference_update(previous_uninstall_tasks)

                for blocker in self._blocker_parents.leaf_nodes():
                        self.spinner.update()
                        root_config = self.roots[blocker.root]
                        virtuals = root_config.settings.getvirtuals()
                        myroot = blocker.root
                        initial_db = self.trees[myroot]["vartree"].dbapi
                        final_db = self.mydbapi[myroot]
                        
                        provider_virtual = False
                        if blocker.cp in virtuals and \
                                not self._have_new_virt(blocker.root, blocker.cp):
                                provider_virtual = True

                        if provider_virtual:
                                atoms = []
                                for provider_entry in virtuals[blocker.cp]:
                                        provider_cp = \
                                                portage.dep_getkey(provider_entry)
                                        atoms.append(blocker.atom.replace(
                                                blocker.cp, provider_cp))
                        else:
                                atoms = [blocker.atom]

                        blocked_initial = []
                        for atom in atoms:
                                blocked_initial.extend(initial_db.match_pkgs(atom))

                        blocked_final = []
                        for atom in atoms:
                                blocked_final.extend(final_db.match_pkgs(atom))

                        if not blocked_initial and not blocked_final:
                                parent_pkgs = self._blocker_parents.parent_nodes(blocker)
                                self._blocker_parents.remove(blocker)
                                # Discard any parents that don't have any more blockers.
                                for pkg in parent_pkgs:
                                        self._irrelevant_blockers.add(blocker, pkg)
                                        if not self._blocker_parents.child_nodes(pkg):
                                                self._blocker_parents.remove(pkg)
                                continue
                        for parent in self._blocker_parents.parent_nodes(blocker):
                                unresolved_blocks = False
                                depends_on_order = set()
                                for pkg in blocked_initial:
                                        if pkg.slot_atom == parent.slot_atom:
                                                # TODO: Support blocks within slots in cases where it
                                                # might make sense.  For example, a new version might
                                                # require that the old version be uninstalled at build
                                                # time.
                                                continue
                                        if parent.installed:
                                                # Two currently installed packages conflict with
                                                # eachother. Ignore this case since the damage
                                                # is already done and this would be likely to
                                                # confuse users if displayed like a normal blocker.
                                                continue
                                        if parent.operation == "merge":
                                                # Maybe the blocked package can be replaced or simply
                                                # unmerged to resolve this block.
                                                depends_on_order.add((pkg, parent))
                                                continue
                                        # None of the above blocker resolutions techniques apply,
                                        # so apparently this one is unresolvable.
                                        unresolved_blocks = True
                                for pkg in blocked_final:
                                        if pkg.slot_atom == parent.slot_atom:
                                                # TODO: Support blocks within slots.
                                                continue
                                        if parent.operation == "nomerge" and \
                                                pkg.operation == "nomerge":
                                                # This blocker will be handled the next time that a
                                                # merge of either package is triggered.
                                                continue

                                        # Maybe the blocking package can be
                                        # unmerged to resolve this block.
                                        if parent.operation == "merge" and pkg.installed:
                                                depends_on_order.add((pkg, parent))
                                                continue
                                        elif parent.operation == "nomerge":
                                                depends_on_order.add((parent, pkg))
                                                continue
                                        # None of the above blocker resolutions techniques apply,
                                        # so apparently this one is unresolvable.
                                        unresolved_blocks = True

                                # Make sure we don't unmerge any package that have been pulled
                                # into the graph.
                                if not unresolved_blocks and depends_on_order:
                                        for inst_pkg, inst_task in depends_on_order:
                                                if self.digraph.contains(inst_pkg) and \
                                                        self.digraph.parent_nodes(inst_pkg):
                                                        unresolved_blocks = True
                                                        break

                                if not unresolved_blocks and depends_on_order:
                                        for inst_pkg, inst_task in depends_on_order:
                                                uninst_task = Package(built=inst_pkg.built,
                                                        cpv=inst_pkg.cpv, installed=inst_pkg.installed,
                                                        metadata=inst_pkg.metadata,
                                                        operation="uninstall",
                                                        root_config=inst_pkg.root_config,
                                                        type_name=inst_pkg.type_name)
                                                self._pkg_cache[uninst_task] = uninst_task
                                                # Enforce correct merge order with a hard dep.
                                                self.digraph.addnode(uninst_task, inst_task,
                                                        priority=BlockerDepPriority.instance)
                                                # Count references to this blocker so that it can be
                                                # invalidated after nodes referencing it have been
                                                # merged.
                                                self._blocker_uninstalls.addnode(uninst_task, blocker)
                                if not unresolved_blocks and not depends_on_order:
                                        self._irrelevant_blockers.add(blocker, parent)
                                        self._blocker_parents.remove_edge(blocker, parent)
                                        if not self._blocker_parents.parent_nodes(blocker):
                                                self._blocker_parents.remove(blocker)
                                        if not self._blocker_parents.child_nodes(parent):
                                                self._blocker_parents.remove(parent)
                                if unresolved_blocks:
                                        self._unsolvable_blockers.add(blocker, parent)

                return True

        def _accept_blocker_conflicts(self):
                acceptable = False
                for x in ("--buildpkgonly", "--fetchonly",
                        "--fetch-all-uri", "--nodeps", "--pretend"):
                        if x in self.myopts:
                                acceptable = True
                                break
                return acceptable

        def _merge_order_bias(self, mygraph):
                """Order nodes from highest to lowest overall reference count for
                optimal leaf node selection."""
                node_info = {}
                for node in mygraph.order:
                        node_info[node] = len(mygraph.parent_nodes(node))
                def cmp_merge_preference(node1, node2):
                        return node_info[node2] - node_info[node1]
                mygraph.order.sort(cmp_merge_preference)

        def altlist(self, reversed=False):

                while self._serialized_tasks_cache is None:
                        self._resolve_conflicts()
                        try:
                                self._serialized_tasks_cache, self._scheduler_graph = \
                                        self._serialize_tasks()
                        except self._serialize_tasks_retry:
                                pass

                retlist = self._serialized_tasks_cache[:]
                if reversed:
                        retlist.reverse()
                return retlist

        def schedulerGraph(self):
                """
                The scheduler graph is identical to the normal one except that
                uninstall edges are reversed in specific cases that require
                conflicting packages to be temporarily installed simultaneously.
                This is intended for use by the Scheduler in it's parallelization
                logic. It ensures that temporary simultaneous installation of
                conflicting packages is avoided when appropriate (especially for
                !!atom blockers), but allowed in specific cases that require it.

                Note that this method calls break_refs() which alters the state of
                internal Package instances such that this depgraph instance should
                not be used to perform any more calculations.
                """
                if self._scheduler_graph is None:
                        self.altlist()
                self.break_refs(self._scheduler_graph.order)
                return self._scheduler_graph

        def break_refs(self, nodes):
                """
                Take a mergelist like that returned from self.altlist() and
                break any references that lead back to the depgraph. This is
                useful if you want to hold references to packages without
                also holding the depgraph on the heap.
                """
                for node in nodes:
                        if hasattr(node, "root_config"):
                                # The FakeVartree references the _package_cache which
                                # references the depgraph. So that Package instances don't
                                # hold the depgraph and FakeVartree on the heap, replace
                                # the RootConfig that references the FakeVartree with the
                                # original RootConfig instance which references the actual
                                # vartree.
                                node.root_config = \
                                        self._trees_orig[node.root_config.root]["root_config"]

        def _resolve_conflicts(self):
                if not self._complete_graph():
                        raise self._unknown_internal_error()

                if not self.validate_blockers():
                        raise self._unknown_internal_error()

                if self._slot_collision_info:
                        self._process_slot_conflicts()

        def _serialize_tasks(self):
                scheduler_graph = self.digraph.copy()
                mygraph=self.digraph.copy()
                # Prune "nomerge" root nodes if nothing depends on them, since
                # otherwise they slow down merge order calculation. Don't remove
                # non-root nodes since they help optimize merge order in some cases
                # such as revdep-rebuild.
                removed_nodes = set()
                while True:
                        for node in mygraph.root_nodes():
                                if not isinstance(node, Package) or \
                                        node.installed or node.onlydeps:
                                        removed_nodes.add(node)
                        if removed_nodes:
                                self.spinner.update()
                                mygraph.difference_update(removed_nodes)
                        if not removed_nodes:
                                break
                        removed_nodes.clear()
                self._merge_order_bias(mygraph)
                def cmp_circular_bias(n1, n2):
                        """
                        RDEPEND is stronger than PDEPEND and this function
                        measures such a strength bias within a circular
                        dependency relationship.
                        """
                        n1_n2_medium = n2 in mygraph.child_nodes(n1,
                                ignore_priority=DepPriority.MEDIUM_SOFT)
                        n2_n1_medium = n1 in mygraph.child_nodes(n2,
                                ignore_priority=DepPriority.MEDIUM_SOFT)
                        if n1_n2_medium == n2_n1_medium:
                                return 0
                        elif n1_n2_medium:
                                return 1
                        return -1
                myblocker_uninstalls = self._blocker_uninstalls.copy()
                retlist=[]
                # Contains uninstall tasks that have been scheduled to
                # occur after overlapping blockers have been installed.
                scheduled_uninstalls = set()
                # Contains any Uninstall tasks that have been ignored
                # in order to avoid the circular deps code path. These
                # correspond to blocker conflicts that could not be
                # resolved.
                ignored_uninstall_tasks = set()
                have_uninstall_task = False
                complete = "complete" in self.myparams
                myblocker_parents = self._blocker_parents.copy()
                asap_nodes = []

                def get_nodes(**kwargs):
                        """
                        Returns leaf nodes excluding Uninstall instances
                        since those should be executed as late as possible.
                        """
                        return [node for node in mygraph.leaf_nodes(**kwargs) \
                                if isinstance(node, Package) and \
                                        (node.operation != "uninstall" or \
                                        node in scheduled_uninstalls)]

                # sys-apps/portage needs special treatment if ROOT="/"
                running_root = self._running_root.root
                from portage.const import PORTAGE_PACKAGE_ATOM
                runtime_deps = InternalPackageSet(
                        initial_atoms=[PORTAGE_PACKAGE_ATOM])
                running_portage = self.trees[running_root]["vartree"].dbapi.match_pkgs(
                        PORTAGE_PACKAGE_ATOM)
                replacement_portage = self.mydbapi[running_root].match_pkgs(
                        PORTAGE_PACKAGE_ATOM)

                if running_portage:
                        running_portage = running_portage[0]
                else:
                        running_portage = None

                if replacement_portage:
                        replacement_portage = replacement_portage[0]
                else:
                        replacement_portage = None

                if replacement_portage == running_portage:
                        replacement_portage = None

                if replacement_portage is not None:
                        # update from running_portage to replacement_portage asap
                        asap_nodes.append(replacement_portage)

                if running_portage is not None:
                        try:
                                portage_rdepend = self._select_atoms_highest_available(
                                        running_root, running_portage.metadata["RDEPEND"],
                                        myuse=running_portage.use.enabled,
                                        parent=running_portage, strict=False)
                        except portage.exception.InvalidDependString, e:
                                portage.writemsg("!!! Invalid RDEPEND in " + \
                                        "'%svar/db/pkg/%s/RDEPEND': %s\n" % \
                                        (running_root, running_portage.cpv, e), noiselevel=-1)
                                del e
                                portage_rdepend = []
                        runtime_deps.update(atom for atom in portage_rdepend \
                                if not atom.startswith("!"))

                ignore_priority_soft_range = [None]
                ignore_priority_soft_range.extend(
                        xrange(DepPriority.MIN, DepPriority.MEDIUM_SOFT + 1))
                tree_mode = "--tree" in self.myopts
                # Tracks whether or not the current iteration should prefer asap_nodes
                # if available.  This is set to False when the previous iteration
                # failed to select any nodes.  It is reset whenever nodes are
                # successfully selected.
                prefer_asap = True

                # By default, try to avoid selecting root nodes whenever possible. This
                # helps ensure that the maximimum possible number of soft dependencies
                # have been removed from the graph before their parent nodes have
                # selected. This is especially important when those dependencies are
                # going to be rebuilt by revdep-rebuild or `emerge -e system` after the
                # CHOST has been changed (like when building a stage3 from a stage2).
                accept_root_node = False

                # State of prefer_asap and accept_root_node flags for successive
                # iterations that loosen the criteria for node selection.
                #
                # iteration   prefer_asap   accept_root_node
                # 1           True          False
                # 2           False         False
                # 3           False         True
                #
                # If no nodes are selected on the 3rd iteration, it is due to
                # unresolved blockers or circular dependencies.

                while not mygraph.empty():
                        self.spinner.update()
                        selected_nodes = None
                        ignore_priority = None
                        if prefer_asap and asap_nodes:
                                """ASAP nodes are merged before their soft deps."""
                                asap_nodes = [node for node in asap_nodes \
                                        if mygraph.contains(node)]
                                for node in asap_nodes:
                                        if not mygraph.child_nodes(node,
                                                ignore_priority=DepPriority.SOFT):
                                                selected_nodes = [node]
                                                asap_nodes.remove(node)
                                                break
                        if not selected_nodes and \
                                not (prefer_asap and asap_nodes):
                                for ignore_priority in ignore_priority_soft_range:
                                        nodes = get_nodes(ignore_priority=ignore_priority)
                                        if nodes:
                                                break
                                if nodes:
                                        if ignore_priority is None and not tree_mode:
                                                # Greedily pop all of these nodes since no relationship
                                                # has been ignored.  This optimization destroys --tree
                                                # output, so it's disabled in reversed mode. If there
                                                # is a mix of merge and uninstall nodes, save the
                                                # uninstall nodes from later since sometimes a merge
                                                # node will render an install node unnecessary, and
                                                # we want to avoid doing a separate uninstall task in
                                                # that case.
                                                merge_nodes = [node for node in nodes \
                                                        if node.operation == "merge"]
                                                if merge_nodes:
                                                        selected_nodes = merge_nodes
                                                else:
                                                        selected_nodes = nodes
                                        else:
                                                # For optimal merge order:
                                                #  * Only pop one node.
                                                #  * Removing a root node (node without a parent)
                                                #    will not produce a leaf node, so avoid it.
                                                for node in nodes:
                                                        if mygraph.parent_nodes(node):
                                                                # found a non-root node
                                                                selected_nodes = [node]
                                                                break
                                                if not selected_nodes and \
                                                        (accept_root_node or ignore_priority is None):
                                                        # settle for a root node
                                                        selected_nodes = [nodes[0]]

                        if not selected_nodes:
                                nodes = get_nodes(ignore_priority=DepPriority.MEDIUM)
                                if nodes:
                                        """Recursively gather a group of nodes that RDEPEND on
                                        eachother.  This ensures that they are merged as a group
                                        and get their RDEPENDs satisfied as soon as possible."""
                                        def gather_deps(ignore_priority,
                                                mergeable_nodes, selected_nodes, node):
                                                if node in selected_nodes:
                                                        return True
                                                if node not in mergeable_nodes:
                                                        return False
                                                if node == replacement_portage and \
                                                        mygraph.child_nodes(node,
                                                        ignore_priority=DepPriority.MEDIUM_SOFT):
                                                        # Make sure that portage always has all of it's
                                                        # RDEPENDs installed first.
                                                        return False
                                                selected_nodes.add(node)
                                                for child in mygraph.child_nodes(node,
                                                        ignore_priority=ignore_priority):
                                                        if not gather_deps(ignore_priority,
                                                                mergeable_nodes, selected_nodes, child):
                                                                return False
                                                return True
                                        mergeable_nodes = set(nodes)
                                        if prefer_asap and asap_nodes:
                                                nodes = asap_nodes
                                        for ignore_priority in xrange(DepPriority.SOFT,
                                                DepPriority.MEDIUM_SOFT + 1):
                                                for node in nodes:
                                                        if nodes is not asap_nodes and \
                                                                not accept_root_node and \
                                                                not mygraph.parent_nodes(node):
                                                                continue
                                                        selected_nodes = set()
                                                        if gather_deps(ignore_priority,
                                                                mergeable_nodes, selected_nodes, node):
                                                                break
                                                        else:
                                                                selected_nodes = None
                                                if selected_nodes:
                                                        break

                                        # If any nodes have been selected here, it's always
                                        # possible that anything up to a MEDIUM_SOFT priority
                                        # relationship has been ignored. This state is recorded
                                        # in ignore_priority so that relevant nodes will be
                                        # added to asap_nodes when appropriate.
                                        if selected_nodes:
                                                ignore_priority = DepPriority.MEDIUM_SOFT

                                        if prefer_asap and asap_nodes and not selected_nodes:
                                                # We failed to find any asap nodes to merge, so ignore
                                                # them for the next iteration.
                                                prefer_asap = False
                                                continue

                                        if not selected_nodes and not accept_root_node:
                                                # Maybe there are only root nodes left, so accept them
                                                # for the next iteration.
                                                accept_root_node = True
                                                continue

                        if selected_nodes and ignore_priority > DepPriority.SOFT:
                                # Try to merge ignored medium deps as soon as possible.
                                for node in selected_nodes:
                                        children = set(mygraph.child_nodes(node))
                                        soft = children.difference(
                                                mygraph.child_nodes(node,
                                                ignore_priority=DepPriority.SOFT))
                                        medium_soft = children.difference(
                                                mygraph.child_nodes(node,
                                                ignore_priority=DepPriority.MEDIUM_SOFT))
                                        medium_soft.difference_update(soft)
                                        for child in medium_soft:
                                                if child in selected_nodes:
                                                        continue
                                                if child in asap_nodes:
                                                        continue
                                                asap_nodes.append(child)

                        if selected_nodes and len(selected_nodes) > 1:
                                if not isinstance(selected_nodes, list):
                                        selected_nodes = list(selected_nodes)
                                selected_nodes.sort(cmp_circular_bias)

                        if not selected_nodes and not myblocker_uninstalls.is_empty():
                                # An Uninstall task needs to be executed in order to
                                # avoid conflict if possible.
                                min_parent_deps = None
                                uninst_task = None
                                for task in myblocker_uninstalls.leaf_nodes():
                                        # Do some sanity checks so that system or world packages
                                        # don't get uninstalled inappropriately here (only really
                                        # necessary when --complete-graph has not been enabled).

                                        if task in ignored_uninstall_tasks:
                                                continue

                                        if task in scheduled_uninstalls:
                                                # It's been scheduled but it hasn't
                                                # been executed yet due to dependence
                                                # on installation of blocking packages.
                                                continue

                                        root_config = self.roots[task.root]
                                        inst_pkg = self._pkg_cache[
                                                ("installed", task.root, task.cpv, "nomerge")]

                                        if self.digraph.contains(inst_pkg):
                                                continue

                                        forbid_overlap = False
                                        heuristic_overlap = False
                                        for blocker in myblocker_uninstalls.parent_nodes(task):
                                                if blocker.eapi in ("0", "1"):
                                                        heuristic_overlap = True
                                                elif blocker.atom.blocker.overlap.forbid:
                                                        forbid_overlap = True
                                                        break
                                        if forbid_overlap and running_root == task.root:
                                                continue

                                        if heuristic_overlap and running_root == task.root:
                                                # Never uninstall sys-apps/portage or it's essential
                                                # dependencies, except through replacement.
                                                try:
                                                        runtime_dep_atoms = \
                                                                list(runtime_deps.iterAtomsForPackage(task))
                                                except portage.exception.InvalidDependString, e:
                                                        portage.writemsg("!!! Invalid PROVIDE in " + \
                                                                "'%svar/db/pkg/%s/PROVIDE': %s\n" % \
                                                                (task.root, task.cpv, e), noiselevel=-1)
                                                        del e
                                                        continue

                                                # Don't uninstall a runtime dep if it appears
                                                # to be the only suitable one installed.
                                                skip = False
                                                vardb = root_config.trees["vartree"].dbapi
                                                for atom in runtime_dep_atoms:
                                                        other_version = None
                                                        for pkg in vardb.match_pkgs(atom):
                                                                if pkg.cpv == task.cpv and \
                                                                        pkg.metadata["COUNTER"] == \
                                                                        task.metadata["COUNTER"]:
                                                                        continue
                                                                other_version = pkg
                                                                break
                                                        if other_version is None:
                                                                skip = True
                                                                break
                                                if skip:
                                                        continue

                                                # For packages in the system set, don't take
                                                # any chances. If the conflict can't be resolved
                                                # by a normal replacement operation then abort.
                                                skip = False
                                                try:
                                                        for atom in root_config.sets[
                                                                "system"].iterAtomsForPackage(task):
                                                                skip = True
                                                                break
                                                except portage.exception.InvalidDependString, e:
                                                        portage.writemsg("!!! Invalid PROVIDE in " + \
                                                                "'%svar/db/pkg/%s/PROVIDE': %s\n" % \
                                                                (task.root, task.cpv, e), noiselevel=-1)
                                                        del e
                                                        skip = True
                                                if skip:
                                                        continue

                                        # Note that the world check isn't always
                                        # necessary since self._complete_graph() will
                                        # add all packages from the system and world sets to the
                                        # graph. This just allows unresolved conflicts to be
                                        # detected as early as possible, which makes it possible
                                        # to avoid calling self._complete_graph() when it is
                                        # unnecessary due to blockers triggering an abortion.
                                        if not complete:
                                                # For packages in the world set, go ahead an uninstall
                                                # when necessary, as long as the atom will be satisfied
                                                # in the final state.
                                                graph_db = self.mydbapi[task.root]
                                                skip = False
                                                try:
                                                        for atom in root_config.sets[
                                                                "world"].iterAtomsForPackage(task):
                                                                satisfied = False
                                                                for pkg in graph_db.match_pkgs(atom):
                                                                        if pkg == inst_pkg:
                                                                                continue
                                                                        satisfied = True
                                                                        break
                                                                if not satisfied:
                                                                        skip = True
                                                                        break
                                                except portage.exception.InvalidDependString, e:
                                                        portage.writemsg("!!! Invalid PROVIDE in " + \
                                                                "'%svar/db/pkg/%s/PROVIDE': %s\n" % \
                                                                (task.root, task.cpv, e), noiselevel=-1)
                                                        del e
                                                        skip = True
                                                if skip:
                                                        continue

                                        # Check the deps of parent nodes to ensure that
                                        # the chosen task produces a leaf node. Maybe
                                        # this can be optimized some more to make the
                                        # best possible choice, but the current algorithm
                                        # is simple and should be near optimal for most
                                        # common cases.
                                        parent_deps = set()
                                        for parent in mygraph.parent_nodes(task):
                                                parent_deps.update(mygraph.child_nodes(parent,
                                                        ignore_priority=DepPriority.MEDIUM_SOFT))
                                        parent_deps.remove(task)
                                        if min_parent_deps is None or \
                                                len(parent_deps) < min_parent_deps:
                                                min_parent_deps = len(parent_deps)
                                                uninst_task = task

                                if uninst_task is not None:
                                        # The uninstall is performed only after blocking
                                        # packages have been merged on top of it. File
                                        # collisions between blocking packages are detected
                                        # and removed from the list of files to be uninstalled.
                                        scheduled_uninstalls.add(uninst_task)
                                        parent_nodes = mygraph.parent_nodes(uninst_task)

                                        # Reverse the parent -> uninstall edges since we want
                                        # to do the uninstall after blocking packages have
                                        # been merged on top of it.
                                        mygraph.remove(uninst_task)
                                        for blocked_pkg in parent_nodes:
                                                mygraph.add(blocked_pkg, uninst_task,
                                                        priority=BlockerDepPriority.instance)
                                                scheduler_graph.remove_edge(uninst_task, blocked_pkg)
                                                scheduler_graph.add(blocked_pkg, uninst_task,
                                                        priority=BlockerDepPriority.instance)

                                else:
                                        # None of the Uninstall tasks are acceptable, so
                                        # the corresponding blockers are unresolvable.
                                        # We need to drop an Uninstall task here in order
                                        # to avoid the circular deps code path, but the
                                        # blocker will still be counted as an unresolved
                                        # conflict.
                                        for node in myblocker_uninstalls.leaf_nodes():
                                                try:
                                                        mygraph.remove(node)
                                                except KeyError:
                                                        pass
                                                else:
                                                        ignored_uninstall_tasks.add(node)
                                                        break

                                # After dropping an Uninstall task, reset
                                # the state variables for leaf node selection and
                                # continue trying to select leaf nodes.
                                prefer_asap = True
                                accept_root_node = False
                                continue

                        if not selected_nodes:
                                self._circular_deps_for_display = mygraph
                                raise self._unknown_internal_error()

                        # At this point, we've succeeded in selecting one or more nodes, so
                        # it's now safe to reset the prefer_asap and accept_root_node flags
                        # to their default states.
                        prefer_asap = True
                        accept_root_node = False

                        mygraph.difference_update(selected_nodes)

                        for node in selected_nodes:
                                if isinstance(node, Package) and \
                                        node.operation == "nomerge":
                                        continue

                                # Handle interactions between blockers
                                # and uninstallation tasks.
                                solved_blockers = set()
                                uninst_task = None
                                if isinstance(node, Package) and \
                                        "uninstall" == node.operation:
                                        have_uninstall_task = True
                                        uninst_task = node
                                else:
                                        vardb = self.trees[node.root]["vartree"].dbapi
                                        previous_cpv = vardb.match(node.slot_atom)
                                        if previous_cpv:
                                                # The package will be replaced by this one, so remove
                                                # the corresponding Uninstall task if necessary.
                                                previous_cpv = previous_cpv[0]
                                                uninst_task = \
                                                        ("installed", node.root, previous_cpv, "uninstall")
                                                try:
                                                        mygraph.remove(uninst_task)
                                                except KeyError:
                                                        pass

                                if uninst_task is not None and \
                                        uninst_task not in ignored_uninstall_tasks and \
                                        myblocker_uninstalls.contains(uninst_task):
                                        blocker_nodes = myblocker_uninstalls.parent_nodes(uninst_task)
                                        myblocker_uninstalls.remove(uninst_task)
                                        # Discard any blockers that this Uninstall solves.
                                        for blocker in blocker_nodes:
                                                if not myblocker_uninstalls.child_nodes(blocker):
                                                        myblocker_uninstalls.remove(blocker)
                                                        solved_blockers.add(blocker)

                                retlist.append(node)

                                if (isinstance(node, Package) and \
                                        "uninstall" == node.operation) or \
                                        (uninst_task is not None and \
                                        uninst_task in scheduled_uninstalls):
                                        # Include satisfied blockers in the merge list
                                        # since the user might be interested and also
                                        # it serves as an indicator that blocking packages
                                        # will be temporarily installed simultaneously.
                                        for blocker in solved_blockers:
                                                retlist.append(Blocker(atom=blocker.atom,
                                                        root=blocker.root, eapi=blocker.eapi,
                                                        satisfied=True))

                unsolvable_blockers = set(self._unsolvable_blockers.leaf_nodes())
                for node in myblocker_uninstalls.root_nodes():
                        unsolvable_blockers.add(node)

                for blocker in unsolvable_blockers:
                        retlist.append(blocker)

                # If any Uninstall tasks need to be executed in order
                # to avoid a conflict, complete the graph with any
                # dependencies that may have been initially
                # neglected (to ensure that unsafe Uninstall tasks
                # are properly identified and blocked from execution).
                if have_uninstall_task and \
                        not complete and \
                        not unsolvable_blockers:
                        self.myparams.add("complete")
                        raise self._serialize_tasks_retry("")

                if unsolvable_blockers and \
                        not self._accept_blocker_conflicts():
                        self._unsatisfied_blockers_for_display = unsolvable_blockers
                        self._serialized_tasks_cache = retlist[:]
                        self._scheduler_graph = scheduler_graph
                        raise self._unknown_internal_error()

                if self._slot_collision_info and \
                        not self._accept_blocker_conflicts():
                        self._serialized_tasks_cache = retlist[:]
                        self._scheduler_graph = scheduler_graph
                        raise self._unknown_internal_error()

                return retlist, scheduler_graph

        def _show_circular_deps(self, mygraph):
                # No leaf nodes are available, so we have a circular
                # dependency panic situation.  Reduce the noise level to a
                # minimum via repeated elimination of root nodes since they
                # have no parents and thus can not be part of a cycle.
                while True:
                        root_nodes = mygraph.root_nodes(
                                ignore_priority=DepPriority.MEDIUM_SOFT)
                        if not root_nodes:
                                break
                        mygraph.difference_update(root_nodes)
                # Display the USE flags that are enabled on nodes that are part
                # of dependency cycles in case that helps the user decide to
                # disable some of them.
                display_order = []
                tempgraph = mygraph.copy()
                while not tempgraph.empty():
                        nodes = tempgraph.leaf_nodes()
                        if not nodes:
                                node = tempgraph.order[0]
                        else:
                                node = nodes[0]
                        display_order.append(node)
                        tempgraph.remove(node)
                display_order.reverse()
                self.myopts.pop("--quiet", None)
                self.myopts.pop("--verbose", None)
                self.myopts["--tree"] = True
                portage.writemsg("\n\n", noiselevel=-1)
                self.display(display_order)
                prefix = colorize("BAD", " * ")
                portage.writemsg("\n", noiselevel=-1)
                portage.writemsg(prefix + "Error: circular dependencies:\n",
                        noiselevel=-1)
                portage.writemsg("\n", noiselevel=-1)
                mygraph.debug_print()
                portage.writemsg("\n", noiselevel=-1)
                portage.writemsg(prefix + "Note that circular dependencies " + \
                        "can often be avoided by temporarily\n", noiselevel=-1)
                portage.writemsg(prefix + "disabling USE flags that trigger " + \
                        "optional dependencies.\n", noiselevel=-1)

        def _show_merge_list(self):
                if self._serialized_tasks_cache is not None and \
                        not (self._displayed_list and \
                        (self._displayed_list == self._serialized_tasks_cache or \
                        self._displayed_list == \
                                list(reversed(self._serialized_tasks_cache)))):
                        display_list = self._serialized_tasks_cache[:]
                        if "--tree" in self.myopts:
                                display_list.reverse()
                        self.display(display_list)

        def _show_unsatisfied_blockers(self, blockers):
                self._show_merge_list()
                msg = "Error: The above package list contains " + \
                        "packages which cannot be installed " + \
                        "at the same time on the same system."
                prefix = colorize("BAD", " * ")
                from textwrap import wrap
                portage.writemsg("\n", noiselevel=-1)
                for line in wrap(msg, 70):
                        portage.writemsg(prefix + line + "\n", noiselevel=-1)
                if "--quiet" not in self.myopts:
                        show_blocker_docs_link()

        def display(self, mylist, favorites=[], verbosity=None):

                # This is used to prevent display_problems() from
                # redundantly displaying this exact same merge list
                # again via _show_merge_list().
                self._displayed_list = mylist

                if verbosity is None:
                        verbosity = ("--quiet" in self.myopts and 1 or \
                                "--verbose" in self.myopts and 3 or 2)
                favorites_set = InternalPackageSet(favorites)
                oneshot = "--oneshot" in self.myopts or \
                        "--onlydeps" in self.myopts
                columns = "--columns" in self.myopts
                changelogs=[]
                p=[]
                blockers = []

                counters = PackageCounters()

                if verbosity == 1 and "--verbose" not in self.myopts:
                        def create_use_string(*args):
                                return ""
                else:
                        def create_use_string(name, cur_iuse, iuse_forced, cur_use,
                                old_iuse, old_use,
                                is_new, reinst_flags,
                                all_flags=(verbosity == 3 or "--quiet" in self.myopts),
                                alphabetical=("--alphabetical" in self.myopts)):
                                enabled = []
                                if alphabetical:
                                        disabled = enabled
                                        removed = enabled
                                else:
                                        disabled = []
                                        removed = []
                                cur_iuse = set(cur_iuse)
                                enabled_flags = cur_iuse.intersection(cur_use)
                                removed_iuse = set(old_iuse).difference(cur_iuse)
                                any_iuse = cur_iuse.union(old_iuse)
                                any_iuse = list(any_iuse)
                                any_iuse.sort()
                                for flag in any_iuse:
                                        flag_str = None
                                        isEnabled = False
                                        reinst_flag = reinst_flags and flag in reinst_flags
                                        if flag in enabled_flags:
                                                isEnabled = True
                                                if is_new or flag in old_use and \
                                                        (all_flags or reinst_flag):
                                                        flag_str = red(flag)
                                                elif flag not in old_iuse:
                                                        flag_str = yellow(flag) + "%*"
                                                elif flag not in old_use:
                                                        flag_str = green(flag) + "*"
                                        elif flag in removed_iuse:
                                                if all_flags or reinst_flag:
                                                        flag_str = yellow("-" + flag) + "%"
                                                        if flag in old_use:
                                                                flag_str += "*"
                                                        flag_str = "(" + flag_str + ")"
                                                        removed.append(flag_str)
                                                continue
                                        else:
                                                if is_new or flag in old_iuse and \
                                                        flag not in old_use and \
                                                        (all_flags or reinst_flag):
                                                        flag_str = blue("-" + flag)
                                                elif flag not in old_iuse:
                                                        flag_str = yellow("-" + flag)
                                                        if flag not in iuse_forced:
                                                                flag_str += "%"
                                                elif flag in old_use:
                                                        flag_str = green("-" + flag) + "*"
                                        if flag_str:
                                                if flag in iuse_forced:
                                                        flag_str = "(" + flag_str + ")"
                                                if isEnabled:
                                                        enabled.append(flag_str)
                                                else:
                                                        disabled.append(flag_str)

                                if alphabetical:
                                        ret = " ".join(enabled)
                                else:
                                        ret = " ".join(enabled + disabled + removed)
                                if ret:
                                        ret = '%s="%s" ' % (name, ret)
                                return ret

                repo_display = RepoDisplay(self.roots)

                tree_nodes = []
                display_list = []
                mygraph = self.digraph.copy()

                # If there are any Uninstall instances, add the corresponding
                # blockers to the digraph (useful for --tree display).

                executed_uninstalls = set(node for node in mylist \
                        if isinstance(node, Package) and node.operation == "unmerge")

                for uninstall in self._blocker_uninstalls.leaf_nodes():
                        uninstall_parents = \
                                self._blocker_uninstalls.parent_nodes(uninstall)
                        if not uninstall_parents:
                                continue

                        # Remove the corresponding "nomerge" node and substitute
                        # the Uninstall node.
                        inst_pkg = self._pkg_cache[
                                ("installed", uninstall.root, uninstall.cpv, "nomerge")]
                        try:
                                mygraph.remove(inst_pkg)
                        except KeyError:
                                pass

                        try:
                                inst_pkg_blockers = self._blocker_parents.child_nodes(inst_pkg)
                        except KeyError:
                                inst_pkg_blockers = []

                        # Break the Package -> Uninstall edges.
                        mygraph.remove(uninstall)

                        # Resolution of a package's blockers
                        # depend on it's own uninstallation.
                        for blocker in inst_pkg_blockers:
                                mygraph.add(uninstall, blocker)

                        # Expand Package -> Uninstall edges into
                        # Package -> Blocker -> Uninstall edges.
                        for blocker in uninstall_parents:
                                mygraph.add(uninstall, blocker)
                                for parent in self._blocker_parents.parent_nodes(blocker):
                                        if parent != inst_pkg:
                                                mygraph.add(blocker, parent)

                        # If the uninstall task did not need to be executed because
                        # of an upgrade, display Blocker -> Upgrade edges since the
                        # corresponding Blocker -> Uninstall edges will not be shown.
                        upgrade_node = \
                                self._slot_pkg_map[uninstall.root].get(uninstall.slot_atom)
                        if upgrade_node is not None and \
                                uninstall not in executed_uninstalls:
                                for blocker in uninstall_parents:
                                        mygraph.add(upgrade_node, blocker)

                unsatisfied_blockers = []
                i = 0
                depth = 0
                shown_edges = set()
                for x in mylist:
                        if isinstance(x, Blocker) and not x.satisfied:
                                unsatisfied_blockers.append(x)
                                continue
                        graph_key = x
                        if "--tree" in self.myopts:
                                depth = len(tree_nodes)
                                while depth and graph_key not in \
                                        mygraph.child_nodes(tree_nodes[depth-1]):
                                                depth -= 1
                                if depth:
                                        tree_nodes = tree_nodes[:depth]
                                        tree_nodes.append(graph_key)
                                        display_list.append((x, depth, True))
                                        shown_edges.add((graph_key, tree_nodes[depth-1]))
                                else:
                                        traversed_nodes = set() # prevent endless circles
                                        traversed_nodes.add(graph_key)
                                        def add_parents(current_node, ordered):
                                                parent_nodes = None
                                                # Do not traverse to parents if this node is an
                                                # an argument or a direct member of a set that has
                                                # been specified as an argument (system or world).
                                                if current_node not in self._set_nodes:
                                                        parent_nodes = mygraph.parent_nodes(current_node)
                                                if parent_nodes:
                                                        child_nodes = set(mygraph.child_nodes(current_node))
                                                        selected_parent = None
                                                        # First, try to avoid a direct cycle.
                                                        for node in parent_nodes:
                                                                if not isinstance(node, (Blocker, Package)):
                                                                        continue
                                                                if node not in traversed_nodes and \
                                                                        node not in child_nodes:
                                                                        edge = (current_node, node)
                                                                        if edge in shown_edges:
                                                                                continue
                                                                        selected_parent = node
                                                                        break
                                                        if not selected_parent:
                                                                # A direct cycle is unavoidable.
                                                                for node in parent_nodes:
                                                                        if not isinstance(node, (Blocker, Package)):
                                                                                continue
                                                                        if node not in traversed_nodes:
                                                                                edge = (current_node, node)
                                                                                if edge in shown_edges:
                                                                                        continue
                                                                                selected_parent = node
                                                                                break
                                                        if selected_parent:
                                                                shown_edges.add((current_node, selected_parent))
                                                                traversed_nodes.add(selected_parent)
                                                                add_parents(selected_parent, False)
                                                display_list.append((current_node,
                                                        len(tree_nodes), ordered))
                                                tree_nodes.append(current_node)
                                        tree_nodes = []
                                        add_parents(graph_key, True)
                        else:
                                display_list.append((x, depth, True))
                mylist = display_list
                for x in unsatisfied_blockers:
                        mylist.append((x, 0, True))

                last_merge_depth = 0
                for i in xrange(len(mylist)-1,-1,-1):
                        graph_key, depth, ordered = mylist[i]
                        if not ordered and depth == 0 and i > 0 \
                                and graph_key == mylist[i-1][0] and \
                                mylist[i-1][1] == 0:
                                # An ordered node got a consecutive duplicate when the tree was
                                # being filled in.
                                del mylist[i]
                                continue
                        if ordered and graph_key[-1] != "nomerge":
                                last_merge_depth = depth
                                continue
                        if depth >= last_merge_depth or \
                                i < len(mylist) - 1 and \
                                depth >= mylist[i+1][1]:
                                        del mylist[i]

                from portage import flatten
                from portage.dep import use_reduce, paren_reduce
                # files to fetch list - avoids counting a same file twice
                # in size display (verbose mode)
                myfetchlist=[]

                # Use this set to detect when all the "repoadd" strings are "[0]"
                # and disable the entire repo display in this case.
                repoadd_set = set()

                for mylist_index in xrange(len(mylist)):
                        x, depth, ordered = mylist[mylist_index]
                        pkg_type = x[0]
                        myroot = x[1]
                        pkg_key = x[2]
                        portdb = self.trees[myroot]["porttree"].dbapi
                        bindb  = self.trees[myroot]["bintree"].dbapi
                        vardb = self.trees[myroot]["vartree"].dbapi
                        vartree = self.trees[myroot]["vartree"]
                        pkgsettings = self.pkgsettings[myroot]

                        fetch=" "
                        indent = " " * depth

                        if isinstance(x, Blocker):
                                if x.satisfied:
                                        blocker_style = "PKG_BLOCKER_SATISFIED"
                                        addl = "%s  %s  " % (colorize(blocker_style, "b"), fetch)
                                else:
                                        blocker_style = "PKG_BLOCKER"
                                        addl = "%s  %s  " % (colorize(blocker_style, "B"), fetch)
                                if ordered:
                                        counters.blocks += 1
                                        if x.satisfied:
                                                counters.blocks_satisfied += 1
                                resolved = portage.key_expand(
                                        str(x.atom).lstrip("!"), mydb=vardb, settings=pkgsettings)
                                if "--columns" in self.myopts and "--quiet" in self.myopts:
                                        addl += " " + colorize(blocker_style, resolved)
                                else:
                                        addl = "[%s %s] %s%s" % \
                                                (colorize(blocker_style, "blocks"),
                                                addl, indent, colorize(blocker_style, resolved))
                                block_parents = self._blocker_parents.parent_nodes(x)
                                block_parents = set([pnode[2] for pnode in block_parents])
                                block_parents = ", ".join(block_parents)
                                if resolved!=x[2]:
                                        addl += colorize(blocker_style,
                                                " (\"%s\" is blocking %s)") % \
                                                (str(x.atom).lstrip("!"), block_parents)
                                else:
                                        addl += colorize(blocker_style,
                                                " (is blocking %s)") % block_parents
                                if isinstance(x, Blocker) and x.satisfied:
                                        if columns:
                                                continue
                                        p.append(addl)
                                else:
                                        blockers.append(addl)
                        else:
                                pkg_status = x[3]
                                pkg_merge = ordered and pkg_status == "merge"
                                if not pkg_merge and pkg_status == "merge":
                                        pkg_status = "nomerge"
                                built = pkg_type != "ebuild"
                                installed = pkg_type == "installed"
                                pkg = x
                                metadata = pkg.metadata
                                ebuild_path = None
                                repo_name = metadata["repository"]
                                if pkg_type == "ebuild":
                                        ebuild_path = portdb.findname(pkg_key)
                                        if not ebuild_path: # shouldn't happen
                                                raise portage.exception.PackageNotFound(pkg_key)
                                        repo_path_real = os.path.dirname(os.path.dirname(
                                                os.path.dirname(ebuild_path)))
                                else:
                                        repo_path_real = portdb.getRepositoryPath(repo_name)
                                pkg_use = list(pkg.use.enabled)
                                try:
                                        restrict = flatten(use_reduce(paren_reduce(
                                                pkg.metadata["RESTRICT"]), uselist=pkg_use))
                                except portage.exception.InvalidDependString, e:
                                        if not pkg.installed:
                                                show_invalid_depstring_notice(x,
                                                        pkg.metadata["RESTRICT"], str(e))
                                                del e
                                                return 1
                                        restrict = []
                                if "ebuild" == pkg_type and x[3] != "nomerge" and \
                                        "fetch" in restrict:
                                        fetch = red("F")
                                        if ordered:
                                                counters.restrict_fetch += 1
                                        if portdb.fetch_check(pkg_key, pkg_use):
                                                fetch = green("f")
                                                if ordered:
                                                        counters.restrict_fetch_satisfied += 1

                                #we need to use "--emptrytree" testing here rather than "empty" param testing because "empty"
                                #param is used for -u, where you still *do* want to see when something is being upgraded.
                                myoldbest = []
                                myinslotlist = None
                                installed_versions = vardb.match(portage.cpv_getkey(pkg_key))
                                if vardb.cpv_exists(pkg_key):
                                        addl="  "+yellow("R")+fetch+"  "
                                        if ordered:
                                                if pkg_merge:
                                                        counters.reinst += 1
                                                elif pkg_status == "uninstall":
                                                        counters.uninst += 1
                                # filter out old-style virtual matches
                                elif installed_versions and \
                                        portage.cpv_getkey(installed_versions[0]) == \
                                        portage.cpv_getkey(pkg_key):
                                        myinslotlist = vardb.match(pkg.slot_atom)
                                        # If this is the first install of a new-style virtual, we
                                        # need to filter out old-style virtual matches.
                                        if myinslotlist and \
                                                portage.cpv_getkey(myinslotlist[0]) != \
                                                portage.cpv_getkey(pkg_key):
                                                myinslotlist = None
                                        if myinslotlist:
                                                myoldbest = myinslotlist[:]
                                                addl = "   " + fetch
                                                if not portage.dep.cpvequal(pkg_key,
                                                        portage.best([pkg_key] + myoldbest)):
                                                        # Downgrade in slot
                                                        addl += turquoise("U")+blue("D")
                                                        if ordered:
                                                                counters.downgrades += 1
                                                else:
                                                        # Update in slot
                                                        addl += turquoise("U") + " "
                                                        if ordered:
                                                                counters.upgrades += 1
                                        else:
                                                # New slot, mark it new.
                                                addl = " " + green("NS") + fetch + "  "
                                                myoldbest = vardb.match(portage.cpv_getkey(pkg_key))
                                                if ordered:
                                                        counters.newslot += 1

                                        if "--changelog" in self.myopts:
                                                inst_matches = vardb.match(pkg.slot_atom)
                                                if inst_matches:
                                                        changelogs.extend(self.calc_changelog(
                                                                portdb.findname(pkg_key),
                                                                inst_matches[0], pkg_key))
                                else:
                                        addl = " " + green("N") + " " + fetch + "  "
                                        if ordered:
                                                counters.new += 1

                                verboseadd = ""
                                repoadd = None

                                if True:
                                        # USE flag display
                                        forced_flags = set()
                                        pkgsettings.setcpv(pkg) # for package.use.{mask,force}
                                        forced_flags.update(pkgsettings.useforce)
                                        forced_flags.update(pkgsettings.usemask)

                                        cur_use = [flag for flag in pkg.use.enabled \
                                                if flag in pkg.iuse.all]
                                        cur_iuse = sorted(pkg.iuse.all)

                                        if myoldbest and myinslotlist:
                                                previous_cpv = myoldbest[0]
                                        else:
                                                previous_cpv = pkg.cpv
                                        if vardb.cpv_exists(previous_cpv):
                                                old_iuse, old_use = vardb.aux_get(
                                                                previous_cpv, ["IUSE", "USE"])
                                                old_iuse = list(set(
                                                        filter_iuse_defaults(old_iuse.split())))
                                                old_iuse.sort()
                                                old_use = old_use.split()
                                                is_new = False
                                        else:
                                                old_iuse = []
                                                old_use = []
                                                is_new = True

                                        old_use = [flag for flag in old_use if flag in old_iuse]

                                        use_expand = pkgsettings["USE_EXPAND"].lower().split()
                                        use_expand.sort()
                                        use_expand.reverse()
                                        use_expand_hidden = \
                                                pkgsettings["USE_EXPAND_HIDDEN"].lower().split()

                                        def map_to_use_expand(myvals, forcedFlags=False,
                                                removeHidden=True):
                                                ret = {}
                                                forced = {}
                                                for exp in use_expand:
                                                        ret[exp] = []
                                                        forced[exp] = set()
                                                        for val in myvals[:]:
                                                                if val.startswith(exp.lower()+"_"):
                                                                        if val in forced_flags:
                                                                                forced[exp].add(val[len(exp)+1:])
                                                                        ret[exp].append(val[len(exp)+1:])
                                                                        myvals.remove(val)
                                                ret["USE"] = myvals
                                                forced["USE"] = [val for val in myvals \
                                                        if val in forced_flags]
                                                if removeHidden:
                                                        for exp in use_expand_hidden:
                                                                ret.pop(exp, None)
                                                if forcedFlags:
                                                        return ret, forced
                                                return ret

                                        # Prevent USE_EXPAND_HIDDEN flags from being hidden if they
                                        # are the only thing that triggered reinstallation.
                                        reinst_flags_map = {}
                                        reinstall_for_flags = self._reinstall_nodes.get(pkg)
                                        reinst_expand_map = None
                                        if reinstall_for_flags:
                                                reinst_flags_map = map_to_use_expand(
                                                        list(reinstall_for_flags), removeHidden=False)
                                                for k in list(reinst_flags_map):
                                                        if not reinst_flags_map[k]:
                                                                del reinst_flags_map[k]
                                                if not reinst_flags_map.get("USE"):
                                                        reinst_expand_map = reinst_flags_map.copy()
                                                        reinst_expand_map.pop("USE", None)
                                        if reinst_expand_map and \
                                                not set(reinst_expand_map).difference(
                                                use_expand_hidden):
                                                use_expand_hidden = \
                                                        set(use_expand_hidden).difference(
                                                        reinst_expand_map)

                                        cur_iuse_map, iuse_forced = \
                                                map_to_use_expand(cur_iuse, forcedFlags=True)
                                        cur_use_map = map_to_use_expand(cur_use)
                                        old_iuse_map = map_to_use_expand(old_iuse)
                                        old_use_map = map_to_use_expand(old_use)

                                        use_expand.sort()
                                        use_expand.insert(0, "USE")
                                        
                                        for key in use_expand:
                                                if key in use_expand_hidden:
                                                        continue
                                                verboseadd += create_use_string(key.upper(),
                                                        cur_iuse_map[key], iuse_forced[key],
                                                        cur_use_map[key], old_iuse_map[key],
                                                        old_use_map[key], is_new,
                                                        reinst_flags_map.get(key))

                                if verbosity == 3:
                                        # size verbose
                                        mysize=0
                                        if pkg_type == "ebuild" and pkg_merge:
                                                try:
                                                        myfilesdict = portdb.getfetchsizes(pkg_key,
                                                                useflags=pkg_use, debug=self.edebug)
                                                except portage.exception.InvalidDependString, e:
                                                        src_uri = portdb.aux_get(pkg_key, ["SRC_URI"])[0]
                                                        show_invalid_depstring_notice(x, src_uri, str(e))
                                                        del e
                                                        return 1
                                                if myfilesdict is None:
                                                        myfilesdict="[empty/missing/bad digest]"
                                                else:
                                                        for myfetchfile in myfilesdict:
                                                                if myfetchfile not in myfetchlist:
                                                                        mysize+=myfilesdict[myfetchfile]
                                                                        myfetchlist.append(myfetchfile)
                                                        if ordered:
                                                                counters.totalsize += mysize
                                                verboseadd += format_size(mysize)

                                        # overlay verbose
                                        # assign index for a previous version in the same slot
                                        has_previous = False
                                        repo_name_prev = None
                                        slot_atom = "%s:%s" % (portage.dep_getkey(pkg_key),
                                                metadata["SLOT"])
                                        slot_matches = vardb.match(slot_atom)
                                        if slot_matches:
                                                has_previous = True
                                                repo_name_prev = vardb.aux_get(slot_matches[0],
                                                        ["repository"])[0]

                                        # now use the data to generate output
                                        if pkg.installed or not has_previous:
                                                repoadd = repo_display.repoStr(repo_path_real)
                                        else:
                                                repo_path_prev = None
                                                if repo_name_prev:
                                                        repo_path_prev = portdb.getRepositoryPath(
                                                                repo_name_prev)
                                                if repo_path_prev == repo_path_real:
                                                        repoadd = repo_display.repoStr(repo_path_real)
                                                else:
                                                        repoadd = "%s=>%s" % (
                                                                repo_display.repoStr(repo_path_prev),
                                                                repo_display.repoStr(repo_path_real))
                                        if repoadd:
                                                repoadd_set.add(repoadd)

                                xs = [portage.cpv_getkey(pkg_key)] + \
                                        list(portage.catpkgsplit(pkg_key)[2:])
                                if xs[2] == "r0":
                                        xs[2] = ""
                                else:
                                        xs[2] = "-" + xs[2]

                                mywidth = 130
                                if "COLUMNWIDTH" in self.settings:
                                        try:
                                                mywidth = int(self.settings["COLUMNWIDTH"])
                                        except ValueError, e:
                                                portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
                                                portage.writemsg(
                                                        "!!! Unable to parse COLUMNWIDTH='%s'\n" % \
                                                        self.settings["COLUMNWIDTH"], noiselevel=-1)
                                                del e
                                oldlp = mywidth - 30
                                newlp = oldlp - 30

                                # Convert myoldbest from a list to a string.
                                if not myoldbest:
                                        myoldbest = ""
                                else:
                                        for pos, key in enumerate(myoldbest):
                                                key = portage.catpkgsplit(key)[2] + \
                                                        "-" + portage.catpkgsplit(key)[3]
                                                if key[-3:] == "-r0":
                                                        key = key[:-3]
                                                myoldbest[pos] = key
                                        myoldbest = blue("["+", ".join(myoldbest)+"]")

                                pkg_cp = xs[0]
                                root_config = self.roots[myroot]
                                system_set = root_config.sets["system"]
                                world_set  = root_config.sets["world"]

                                pkg_system = False
                                pkg_world = False
                                try:
                                        pkg_system = system_set.findAtomForPackage(pkg)
                                        pkg_world  = world_set.findAtomForPackage(pkg)
                                        if not (oneshot or pkg_world) and \
                                                myroot == self.target_root and \
                                                favorites_set.findAtomForPackage(pkg):
                                                # Maybe it will be added to world now.
                                                if create_world_atom(pkg, favorites_set, root_config):
                                                        pkg_world = True
                                except portage.exception.InvalidDependString:
                                        # This is reported elsewhere if relevant.
                                        pass

                                def pkgprint(pkg_str):
                                        if pkg_merge:
                                                if pkg_system:
                                                        return colorize("PKG_MERGE_SYSTEM", pkg_str)
                                                elif pkg_world:
                                                        return colorize("PKG_MERGE_WORLD", pkg_str)
                                                else:
                                                        return colorize("PKG_MERGE", pkg_str)
                                        elif pkg_status == "uninstall":
                                                return colorize("PKG_UNINSTALL", pkg_str)
                                        else:
                                                if pkg_system:
                                                        return colorize("PKG_NOMERGE_SYSTEM", pkg_str)
                                                elif pkg_world:
                                                        return colorize("PKG_NOMERGE_WORLD", pkg_str)
                                                else:
                                                        return colorize("PKG_NOMERGE", pkg_str)

                                try:
                                        properties = flatten(use_reduce(paren_reduce(
                                                pkg.metadata["PROPERTIES"]), uselist=pkg.use.enabled))
                                except portage.exception.InvalidDependString, e:
                                        if not pkg.installed:
                                                show_invalid_depstring_notice(pkg,
                                                        pkg.metadata["PROPERTIES"], str(e))
                                                del e
                                                return 1
                                        properties = []
                                interactive = "interactive" in properties
                                if interactive and pkg.operation == "merge":
                                        addl = colorize("WARN", "I") + addl[1:]
                                        if ordered:
                                                counters.interactive += 1

                                if x[1]!="/":
                                        if myoldbest:
                                                myoldbest +=" "
                                        if "--columns" in self.myopts:
                                                if "--quiet" in self.myopts:
                                                        myprint=addl+" "+indent+pkgprint(pkg_cp)
                                                        myprint=myprint+darkblue(" "+xs[1]+xs[2])+" "
                                                        myprint=myprint+myoldbest
                                                        myprint=myprint+darkgreen("to "+x[1])
                                                        verboseadd = None
                                                else:
                                                        if not pkg_merge:
                                                                myprint = "[%s] %s%s" % \
                                                                        (pkgprint(pkg_status.ljust(13)),
                                                                        indent, pkgprint(pkg.cp))
                                                        else:
                                                                myprint = "[%s %s] %s%s" % \
                                                                        (pkgprint(pkg.type_name), addl,
                                                                        indent, pkgprint(pkg.cp))
                                                        if (newlp-nc_len(myprint)) > 0:
                                                                myprint=myprint+(" "*(newlp-nc_len(myprint)))
                                                        myprint=myprint+"["+darkblue(xs[1]+xs[2])+"] "
                                                        if (oldlp-nc_len(myprint)) > 0:
                                                                myprint=myprint+" "*(oldlp-nc_len(myprint))
                                                        myprint=myprint+myoldbest
                                                        myprint += darkgreen("to " + pkg.root)
                                        else:
                                                if not pkg_merge:
                                                        myprint = "[%s] " % pkgprint(pkg_status.ljust(13))
                                                else:
                                                        myprint = "[" + pkg_type + " " + addl + "] "
                                                myprint += indent + pkgprint(pkg_key) + " " + \
                                                        myoldbest + darkgreen("to " + myroot)
                                else:
                                        if "--columns" in self.myopts:
                                                if "--quiet" in self.myopts:
                                                        myprint=addl+" "+indent+pkgprint(pkg_cp)
                                                        myprint=myprint+" "+green(xs[1]+xs[2])+" "
                                                        myprint=myprint+myoldbest
                                                        verboseadd = None
                                                else:
                                                        if not pkg_merge:
                                                                myprint = "[%s] %s%s" % \
                                                                        (pkgprint(pkg_status.ljust(13)),
                                                                        indent, pkgprint(pkg.cp))
                                                        else:
                                                                myprint = "[%s %s] %s%s" % \
                                                                        (pkgprint(pkg.type_name), addl,
                                                                        indent, pkgprint(pkg.cp))
                                                        if (newlp-nc_len(myprint)) > 0:
                                                                myprint=myprint+(" "*(newlp-nc_len(myprint)))
                                                        myprint=myprint+green(" ["+xs[1]+xs[2]+"] ")
                                                        if (oldlp-nc_len(myprint)) > 0:
                                                                myprint=myprint+(" "*(oldlp-nc_len(myprint)))
                                                        myprint += myoldbest
                                        else:
                                                if not pkg_merge:
                                                        myprint = "[%s] %s%s %s" % \
                                                                (pkgprint(pkg_status.ljust(13)),
                                                                indent, pkgprint(pkg.cpv),
                                                                myoldbest)
                                                else:
                                                        myprint = "[%s %s] %s%s %s" % \
                                                                (pkgprint(pkg_type), addl, indent,
                                                                pkgprint(pkg.cpv), myoldbest)

                                if columns and pkg.operation == "uninstall":
                                        continue
                                p.append((myprint, verboseadd, repoadd))

                                if "--tree" not in self.myopts and \
                                        "--quiet" not in self.myopts and \
                                        not self._opts_no_restart.intersection(self.myopts) and \
                                        pkg.root == self._running_root.root and \
                                        portage.match_from_list(
                                        portage.const.PORTAGE_PACKAGE_ATOM, [pkg]) and \
                                        not vardb.cpv_exists(pkg.cpv) and \
                                        "--quiet" not in self.myopts:
                                                if mylist_index < len(mylist) - 1:
                                                        p.append(colorize("WARN", "*** Portage will stop merging at this point and reload itself,"))
                                                        p.append(colorize("WARN", "    then resume the merge."))

                out = sys.stdout
                show_repos = repoadd_set and repoadd_set != set(["0"])

                for x in p:
                        if isinstance(x, basestring):
                                out.write("%s\n" % (x,))
                                continue

                        myprint, verboseadd, repoadd = x

                        if verboseadd:
                                myprint += " " + verboseadd

                        if show_repos and repoadd:
                                myprint += " " + teal("[%s]" % repoadd)

                        out.write("%s\n" % (myprint,))

                for x in blockers:
                        print x

                if verbosity == 3:
                        print
                        print counters
                        if show_repos:
                                sys.stdout.write(str(repo_display))

                if "--changelog" in self.myopts:
                        print
                        for revision,text in changelogs:
                                print bold('*'+revision)
                                sys.stdout.write(text)

                sys.stdout.flush()
                return os.EX_OK

        def display_problems(self):
                """
                Display problems with the dependency graph such as slot collisions.
                This is called internally by display() to show the problems _after_
                the merge list where it is most likely to be seen, but if display()
                is not going to be called then this method should be called explicitly
                to ensure that the user is notified of problems with the graph.

                All output goes to stderr, except for unsatisfied dependencies which
                go to stdout for parsing by programs such as autounmask.
                """

                # Note that show_masked_packages() sends it's output to
                # stdout, and some programs such as autounmask parse the
                # output in cases when emerge bails out. However, when
                # show_masked_packages() is called for installed packages
                # here, the message is a warning that is more appropriate
                # to send to stderr, so temporarily redirect stdout to
                # stderr. TODO: Fix output code so there's a cleaner way
                # to redirect everything to stderr.
                sys.stdout.flush()
                sys.stderr.flush()
                stdout = sys.stdout
                try:
                        sys.stdout = sys.stderr
                        self._display_problems()
                finally:
                        sys.stdout = stdout
                        sys.stdout.flush()
                        sys.stderr.flush()

                # This goes to stdout for parsing by programs like autounmask.
                for pargs, kwargs in self._unsatisfied_deps_for_display:
                        self._show_unsatisfied_dep(*pargs, **kwargs)

        def _display_problems(self):
                if self._circular_deps_for_display is not None:
                        self._show_circular_deps(
                                self._circular_deps_for_display)

                # The user is only notified of a slot conflict if
                # there are no unresolvable blocker conflicts.
                if self._unsatisfied_blockers_for_display is not None:
                        self._show_unsatisfied_blockers(
                                self._unsatisfied_blockers_for_display)
                else:
                        self._show_slot_collision_notice()

                # TODO: Add generic support for "set problem" handlers so that
                # the below warnings aren't special cases for world only.

                if self._missing_args:
                        world_problems = False
                        if "world" in self._sets:
                                # Filter out indirect members of world (from nested sets)
                                # since only direct members of world are desired here.
                                world_set = self.roots[self.target_root].sets["world"]
                                for arg, atom in self._missing_args:
                                        if arg.name == "world" and atom in world_set:
                                                world_problems = True
                                                break

                        if world_problems:
                                sys.stderr.write("\n!!! Problems have been " + \
                                        "detected with your world file\n")
                                sys.stderr.write("!!! Please run " + \
                                        green("emaint --check world")+"\n\n")

                if self._missing_args:
                        sys.stderr.write("\n" + colorize("BAD", "!!!") + \
                                " Ebuilds for the following packages are either all\n")
                        sys.stderr.write(colorize("BAD", "!!!") + \
                                " masked or don't exist:\n")
                        sys.stderr.write(" ".join(str(atom) for arg, atom in \
                                self._missing_args) + "\n")

                if self._pprovided_args:
                        arg_refs = {}
                        for arg, atom in self._pprovided_args:
                                if isinstance(arg, SetArg):
                                        parent = arg.name
                                        arg_atom = (atom, atom)
                                else:
                                        parent = "args"
                                        arg_atom = (arg.arg, atom)
                                refs = arg_refs.setdefault(arg_atom, [])
                                if parent not in refs:
                                        refs.append(parent)
                        msg = []
                        msg.append(bad("\nWARNING: "))
                        if len(self._pprovided_args) > 1:
                                msg.append("Requested packages will not be " + \
                                        "merged because they are listed in\n")
                        else:
                                msg.append("A requested package will not be " + \
                                        "merged because it is listed in\n")
                        msg.append("package.provided:\n\n")
                        problems_sets = set()
                        for (arg, atom), refs in arg_refs.iteritems():
                                ref_string = ""
                                if refs:
                                        problems_sets.update(refs)
                                        refs.sort()
                                        ref_string = ", ".join(["'%s'" % name for name in refs])
                                        ref_string = " pulled in by " + ref_string
                                msg.append("  %s%s\n" % (colorize("INFORM", str(arg)), ref_string))
                        msg.append("\n")
                        if "world" in problems_sets:
                                msg.append("This problem can be solved in one of the following ways:\n\n")
                                msg.append("  A) Use emaint to clean offending packages from world (if not installed).\n")
                                msg.append("  B) Uninstall offending packages (cleans them from world).\n")
                                msg.append("  C) Remove offending entries from package.provided.\n\n")
                                msg.append("The best course of action depends on the reason that an offending\n")
                                msg.append("package.provided entry exists.\n\n")
                        sys.stderr.write("".join(msg))

                masked_packages = []
                for pkg in self._masked_installed:
                        root_config = pkg.root_config
                        pkgsettings = self.pkgsettings[pkg.root]
                        mreasons = get_masking_status(pkg, pkgsettings, root_config)
                        masked_packages.append((root_config, pkgsettings,
                                pkg.cpv, pkg.metadata, mreasons))
                if masked_packages:
                        sys.stderr.write("\n" + colorize("BAD", "!!!") + \
                                " The following installed packages are masked:\n")
                        show_masked_packages(masked_packages)
                        show_mask_docs()
                        print

        def calc_changelog(self,ebuildpath,current,next):
                if ebuildpath == None or not os.path.exists(ebuildpath):
                        return []
                current = '-'.join(portage.catpkgsplit(current)[1:])
                if current.endswith('-r0'):
                        current = current[:-3]
                next = '-'.join(portage.catpkgsplit(next)[1:])
                if next.endswith('-r0'):
                        next = next[:-3]
                changelogpath = os.path.join(os.path.split(ebuildpath)[0],'ChangeLog')
                try:
                        changelog = open(changelogpath).read()
                except SystemExit, e:
                        raise # Needed else can't exit
                except:
                        return []
                divisions = self.find_changelog_tags(changelog)
                #print 'XX from',current,'to',next
                #for div,text in divisions: print 'XX',div
                # skip entries for all revisions above the one we are about to emerge
                for i in range(len(divisions)):
                        if divisions[i][0]==next:
                                divisions = divisions[i:]
                                break
                # find out how many entries we are going to display
                for i in range(len(divisions)):
                        if divisions[i][0]==current:
                                divisions = divisions[:i]
                                break
                else:
                    # couldnt find the current revision in the list. display nothing
                        return []
                return divisions

        def find_changelog_tags(self,changelog):
                divs = []
                release = None
                while 1:
                        match = re.search(r'^\*\ ?([-a-zA-Z0-9_.+]*)(?:\ .*)?\n',changelog,re.M)
                        if match is None:
                                if release is not None:
                                        divs.append((release,changelog))
                                return divs
                        if release is not None:
                                divs.append((release,changelog[:match.start()]))
                        changelog = changelog[match.end():]
                        release = match.group(1)
                        if release.endswith('.ebuild'):
                                release = release[:-7]
                        if release.endswith('-r0'):
                                release = release[:-3]

        def saveNomergeFavorites(self):
                """Find atoms in favorites that are not in the mergelist and add them
                to the world file if necessary."""
                for x in ("--buildpkgonly", "--fetchonly", "--fetch-all-uri",
                        "--oneshot", "--onlydeps", "--pretend"):
                        if x in self.myopts:
                                return
                root_config = self.roots[self.target_root]
                world_set = root_config.sets["world"]

                world_locked = False
                if hasattr(world_set, "lock"):
                        world_set.lock()
                        world_locked = True

                if hasattr(world_set, "load"):
                        world_set.load() # maybe it's changed on disk

                args_set = self._sets["args"]
                portdb = self.trees[self.target_root]["porttree"].dbapi
                added_favorites = set()
                for x in self._set_nodes:
                        pkg_type, root, pkg_key, pkg_status = x
                        if pkg_status != "nomerge":
                                continue

                        try:
                                myfavkey = create_world_atom(x, args_set, root_config)
                                if myfavkey:
                                        if myfavkey in added_favorites:
                                                continue
                                        added_favorites.add(myfavkey)
                        except portage.exception.InvalidDependString, e:
                                writemsg("\n\n!!! '%s' has invalid PROVIDE: %s\n" % \
                                        (pkg_key, str(e)), noiselevel=-1)
                                writemsg("!!! see '%s'\n\n" % os.path.join(
                                        root, portage.VDB_PATH, pkg_key, "PROVIDE"), noiselevel=-1)
                                del e
                all_added = []
                for k in self._sets:
                        if k in ("args", "world") or not root_config.sets[k].world_candidate:
                                continue
                        s = SETPREFIX + k
                        if s in world_set:
                                continue
                        all_added.append(SETPREFIX + k)
                all_added.extend(added_favorites)
                all_added.sort()
                for a in all_added:
                        print ">>> Recording %s in \"world\" favorites file..." % \
                                colorize("INFORM", str(a))
                if all_added:
                        world_set.update(all_added)

                if world_locked:
                        world_set.unlock()

        def loadResumeCommand(self, resume_data, skip_masked=False):
                """
                Add a resume command to the graph and validate it in the process.  This
                will raise a PackageNotFound exception if a package is not available.
                """

                if not isinstance(resume_data, dict):
                        return False

                mergelist = resume_data.get("mergelist")
                if not isinstance(mergelist, list):
                        mergelist = []

                fakedb = self.mydbapi
                trees = self.trees
                serialized_tasks = []
                masked_tasks = []
                for x in mergelist:
                        if not (isinstance(x, list) and len(x) == 4):
                                continue
                        pkg_type, myroot, pkg_key, action = x
                        if pkg_type not in self.pkg_tree_map:
                                continue
                        if action != "merge":
                                continue
                        tree_type = self.pkg_tree_map[pkg_type]
                        mydb = trees[myroot][tree_type].dbapi
                        db_keys = list(self._trees_orig[myroot][
                                tree_type].dbapi._aux_cache_keys)
                        try:
                                metadata = izip(db_keys, mydb.aux_get(pkg_key, db_keys))
                        except KeyError:
                                # It does no exist or it is corrupt.
                                if action == "uninstall":
                                        continue
                                raise portage.exception.PackageNotFound(pkg_key)
                        installed = action == "uninstall"
                        built = pkg_type != "ebuild"
                        root_config = self.roots[myroot]
                        pkg = Package(built=built, cpv=pkg_key,
                                installed=installed, metadata=metadata,
                                operation=action, root_config=root_config,
                                type_name=pkg_type)
                        if pkg_type == "ebuild":
                                pkgsettings = self.pkgsettings[myroot]
                                pkgsettings.setcpv(pkg)
                                pkg.metadata["USE"] = pkgsettings["PORTAGE_USE"]
                        self._pkg_cache[pkg] = pkg

                        root_config = self.roots[pkg.root]
                        if "merge" == pkg.operation and \
                                not visible(root_config.settings, pkg):
                                if skip_masked:
                                        masked_tasks.append(Dependency(root=pkg.root, parent=pkg))
                                else:
                                        self._unsatisfied_deps_for_display.append(
                                                ((pkg.root, "="+pkg.cpv), {"myparent":None}))

                        fakedb[myroot].cpv_inject(pkg)
                        serialized_tasks.append(pkg)
                        self.spinner.update()

                if self._unsatisfied_deps_for_display:
                        return False

                if not serialized_tasks or "--nodeps" in self.myopts:
                        self._serialized_tasks_cache = serialized_tasks
                        self._scheduler_graph = self.digraph
                else:
                        self._select_package = self._select_pkg_from_graph
                        self.myparams.add("selective")

                        favorites = resume_data.get("favorites")
                        args_set = self._sets["args"]
                        if isinstance(favorites, list):
                                args = self._load_favorites(favorites)
                        else:
                                args = []

                        for task in serialized_tasks:
                                if isinstance(task, Package) and \
                                        task.operation == "merge":
                                        if not self._add_pkg(task, None):
                                                return False

                        # Packages for argument atoms need to be explicitly
                        # added via _add_pkg() so that they are included in the
                        # digraph (needed at least for --tree display).
                        for arg in args:
                                for atom in arg.set:
                                        pkg, existing_node = self._select_package(
                                                arg.root_config.root, atom)
                                        if existing_node is None and \
                                                pkg is not None:
                                                if not self._add_pkg(pkg, Dependency(atom=atom,
                                                        root=pkg.root, parent=arg)):
                                                        return False

                        # Allow unsatisfied deps here to avoid showing a masking
                        # message for an unsatisfied dep that isn't necessarily
                        # masked.
                        if not self._create_graph(allow_unsatisfied=True):
                                return False
                        if masked_tasks or self._unsatisfied_deps:
                                # This probably means that a required package
                                # was dropped via --skipfirst. It makes the
                                # resume list invalid, so convert it to a
                                # UnsatisfiedResumeDep exception.
                                raise self.UnsatisfiedResumeDep(self,
                                        masked_tasks + self._unsatisfied_deps)
                        self._serialized_tasks_cache = None
                        try:
                                self.altlist()
                        except self._unknown_internal_error:
                                return False

                return True

        def _load_favorites(self, favorites):
                """
                Use a list of favorites to resume state from a
                previous select_files() call. This creates similar
                DependencyArg instances to those that would have
                been created by the original select_files() call.
                This allows Package instances to be matched with
                DependencyArg instances during graph creation.
                """
                root_config = self.roots[self.target_root]
                getSetAtoms = root_config.setconfig.getSetAtoms
                sets = root_config.sets
                args = []
                for x in favorites:
                        if not isinstance(x, basestring):
                                continue
                        if x in ("system", "world"):
                                x = SETPREFIX + x
                        if x.startswith(SETPREFIX):
                                s = x[len(SETPREFIX):]
                                if s not in sets:
                                        continue
                                if s in self._sets:
                                        continue
                                # Recursively expand sets so that containment tests in
                                # self._get_parent_sets() properly match atoms in nested
                                # sets (like if world contains system).
                                expanded_set = InternalPackageSet(
                                        initial_atoms=getSetAtoms(s))
                                self._sets[s] = expanded_set
                                args.append(SetArg(arg=x, set=expanded_set,
                                        root_config=root_config))
                        else:
                                if not portage.isvalidatom(x):
                                        continue
                                args.append(AtomArg(arg=x, atom=x,
                                        root_config=root_config))

                # Create the "args" package set from atoms and
                # packages given as arguments.
                args_set = self._sets["args"]
                for arg in args:
                        if not isinstance(arg, (AtomArg, PackageArg)):
                                continue
                        myatom = arg.atom
                        if myatom in args_set:
                                continue
                        args_set.add(myatom)
                self._set_atoms.update(chain(*self._sets.itervalues()))
                atom_arg_map = self._atom_arg_map
                for arg in args:
                        for atom in arg.set:
                                atom_key = (atom, arg.root_config.root)
                                refs = atom_arg_map.get(atom_key)
                                if refs is None:
                                        refs = []
                                        atom_arg_map[atom_key] = refs
                                        if arg not in refs:
                                                refs.append(arg)
                return args

        class UnsatisfiedResumeDep(portage.exception.PortageException):
                """
                A dependency of a resume list is not installed. This
                can occur when a required package is dropped from the
                merge list via --skipfirst.
                """
                def __init__(self, depgraph, value):
                        portage.exception.PortageException.__init__(self, value)
                        self.depgraph = depgraph

        class _internal_exception(portage.exception.PortageException):
                def __init__(self, value=""):
                        portage.exception.PortageException.__init__(self, value)

        class _unknown_internal_error(_internal_exception):
                """
                Used by the depgraph internally to terminate graph creation.
                The specific reason for the failure should have been dumped
                to stderr, unfortunately, the exact reason for the failure
                may not be known.
                """

        class _serialize_tasks_retry(_internal_exception):
                """
                This is raised by the _serialize_tasks() method when it needs to
                be called again for some reason. The only case that it's currently
                used for is when neglected dependencies need to be added to the
                graph in order to avoid making a potentially unsafe decision.
                """

        class _dep_check_composite_db(portage.dbapi):
                """
                A dbapi-like interface that is optimized for use in dep_check() calls.
                This is built on top of the existing depgraph package selection logic.
                Some packages that have been added to the graph may be masked from this
                view in order to influence the atom preference selection that occurs
                via dep_check().
                """
                def __init__(self, depgraph, root):
                        portage.dbapi.__init__(self)
                        self._depgraph = depgraph
                        self._root = root
                        self._match_cache = {}
                        self._cpv_pkg_map = {}

                def match(self, atom):
                        ret = self._match_cache.get(atom)
                        if ret is not None:
                                return ret[:]
                        orig_atom = atom
                        if "/" not in atom:
                                atom = self._dep_expand(atom)
                        pkg, existing = self._depgraph._select_package(self._root, atom)
                        if not pkg:
                                ret = []
                        else:
                                # Return the highest available from select_package() as well as
                                # any matching slots in the graph db.
                                slots = set()
                                slots.add(pkg.metadata["SLOT"])
                                atom_cp = portage.dep_getkey(atom)
                                if pkg.cp.startswith("virtual/"):
                                        # For new-style virtual lookahead that occurs inside
                                        # dep_check(), examine all slots. This is needed
                                        # so that newer slots will not unnecessarily be pulled in
                                        # when a satisfying lower slot is already installed. For
                                        # example, if virtual/jdk-1.4 is satisfied via kaffe then
                                        # there's no need to pull in a newer slot to satisfy a
                                        # virtual/jdk dependency.
                                        for db, pkg_type, built, installed, db_keys in \
                                                self._depgraph._filtered_trees[self._root]["dbs"]:
                                                for cpv in db.match(atom):
                                                        if portage.cpv_getkey(cpv) != pkg.cp:
                                                                continue
                                                        slots.add(db.aux_get(cpv, ["SLOT"])[0])
                                ret = []
                                if self._visible(pkg):
                                        self._cpv_pkg_map[pkg.cpv] = pkg
                                        ret.append(pkg.cpv)
                                slots.remove(pkg.metadata["SLOT"])
                                while slots:
                                        slot_atom = "%s:%s" % (atom_cp, slots.pop())
                                        pkg, existing = self._depgraph._select_package(
                                                self._root, slot_atom)
                                        if not pkg:
                                                continue
                                        if not self._visible(pkg):
                                                continue
                                        self._cpv_pkg_map[pkg.cpv] = pkg
                                        ret.append(pkg.cpv)
                                if ret:
                                        self._cpv_sort_ascending(ret)
                        self._match_cache[orig_atom] = ret
                        return ret[:]

                def _visible(self, pkg):
                        if pkg.installed and "selective" not in self._depgraph.myparams:
                                try:
                                        arg = self._depgraph._iter_atoms_for_pkg(pkg).next()
                                except (StopIteration, portage.exception.InvalidDependString):
                                        arg = None
                                if arg:
                                        return False
                        if pkg.installed:
                                try:
                                        if not visible(
                                                self._depgraph.pkgsettings[pkg.root], pkg):
                                                return False
                                except portage.exception.InvalidDependString:
                                        pass
                        return True

                def _dep_expand(self, atom):
                        """
                        This is only needed for old installed packages that may
                        contain atoms that are not fully qualified with a specific
                        category. Emulate the cpv_expand() function that's used by
                        dbapi.match() in cases like this. If there are multiple
                        matches, it's often due to a new-style virtual that has
                        been added, so try to filter those out to avoid raising
                        a ValueError.
                        """
                        root_config = self._depgraph.roots[self._root]
                        orig_atom = atom
                        expanded_atoms = self._depgraph._dep_expand(root_config, atom)
                        if len(expanded_atoms) > 1:
                                non_virtual_atoms = []
                                for x in expanded_atoms:
                                        if not portage.dep_getkey(x).startswith("virtual/"):
                                                non_virtual_atoms.append(x)
                                if len(non_virtual_atoms) == 1:
                                        expanded_atoms = non_virtual_atoms
                        if len(expanded_atoms) > 1:
                                # compatible with portage.cpv_expand()
                                raise portage.exception.AmbiguousPackageName(
                                        [portage.dep_getkey(x) for x in expanded_atoms])
                        if expanded_atoms:
                                atom = expanded_atoms[0]
                        else:
                                null_atom = insert_category_into_atom(atom, "null")
                                null_cp = portage.dep_getkey(null_atom)
                                cat, atom_pn = portage.catsplit(null_cp)
                                virts_p = root_config.settings.get_virts_p().get(atom_pn)
                                if virts_p:
                                        # Allow the resolver to choose which virtual.
                                        atom = insert_category_into_atom(atom, "virtual")
                                else:
                                        atom = insert_category_into_atom(atom, "null")
                        return atom

                def aux_get(self, cpv, wants):
                        metadata = self._cpv_pkg_map[cpv].metadata
                        return [metadata.get(x, "") for x in wants]

        class _package_cache(dict):
                def __init__(self, depgraph):
                        dict.__init__(self)
                        self._depgraph = depgraph

                def __setitem__(self, k, v):
                        dict.__setitem__(self, k, v)
                        root_config = self._depgraph.roots[v.root]
                        try:
                                if visible(root_config.settings, v) and \
                                        not (v.installed and \
                                        v.root_config.settings._getMissingKeywords(v.cpv, v.metadata)):
                                        root_config.visible_pkgs.cpv_inject(v)
                        except portage.exception.InvalidDependString:
                                pass

class RepoDisplay(object):
        def __init__(self, roots):
                self._shown_repos = {}
                self._unknown_repo = False
                repo_paths = set()
                for root_config in roots.itervalues():
                        portdir = root_config.settings.get("PORTDIR")
                        if portdir:
                                repo_paths.add(portdir)
                        overlays = root_config.settings.get("PORTDIR_OVERLAY")
                        if overlays:
                                repo_paths.update(overlays.split())
                repo_paths = list(repo_paths)
                self._repo_paths = repo_paths
                self._repo_paths_real = [ os.path.realpath(repo_path) \
                        for repo_path in repo_paths ]

                # pre-allocate index for PORTDIR so that it always has index 0.
                for root_config in roots.itervalues():
                        portdb = root_config.trees["porttree"].dbapi
                        portdir = portdb.porttree_root
                        if portdir:
                                self.repoStr(portdir)

        def repoStr(self, repo_path_real):
                real_index = -1
                if repo_path_real:
                        real_index = self._repo_paths_real.index(repo_path_real)
                if real_index == -1:
                        s = "?"
                        self._unknown_repo = True
                else:
                        shown_repos = self._shown_repos
                        repo_paths = self._repo_paths
                        repo_path = repo_paths[real_index]
                        index = shown_repos.get(repo_path)
                        if index is None:
                                index = len(shown_repos)
                                shown_repos[repo_path] = index
                        s = str(index)
                return s

        def __str__(self):
                output = []
                shown_repos = self._shown_repos
                unknown_repo = self._unknown_repo
                if shown_repos or self._unknown_repo:
                        output.append("Portage tree and overlays:\n")
                show_repo_paths = list(shown_repos)
                for repo_path, repo_index in shown_repos.iteritems():
                        show_repo_paths[repo_index] = repo_path
                if show_repo_paths:
                        for index, repo_path in enumerate(show_repo_paths):
                                output.append(" "+teal("["+str(index)+"]")+" %s\n" % repo_path)
                if unknown_repo:
                        output.append(" "+teal("[?]") + \
                                " indicates that the source repository could not be determined\n")
                return "".join(output)

class PackageCounters(object):

        def __init__(self):
                self.upgrades   = 0
                self.downgrades = 0
                self.new        = 0
                self.newslot    = 0
                self.reinst     = 0
                self.uninst     = 0
                self.blocks     = 0
                self.blocks_satisfied         = 0
                self.totalsize  = 0
                self.restrict_fetch           = 0
                self.restrict_fetch_satisfied = 0
                self.interactive              = 0

        def __str__(self):
                total_installs = self.upgrades + self.downgrades + self.newslot + self.new + self.reinst
                myoutput = []
                details = []
                myoutput.append("Total: %s package" % total_installs)
                if total_installs != 1:
                        myoutput.append("s")
                if total_installs != 0:
                        myoutput.append(" (")
                if self.upgrades > 0:
                        details.append("%s upgrade" % self.upgrades)
                        if self.upgrades > 1:
                                details[-1] += "s"
                if self.downgrades > 0:
                        details.append("%s downgrade" % self.downgrades)
                        if self.downgrades > 1:
                                details[-1] += "s"
                if self.new > 0:
                        details.append("%s new" % self.new)
                if self.newslot > 0:
                        details.append("%s in new slot" % self.newslot)
                        if self.newslot > 1:
                                details[-1] += "s"
                if self.reinst > 0:
                        details.append("%s reinstall" % self.reinst)
                        if self.reinst > 1:
                                details[-1] += "s"
                if self.uninst > 0:
                        details.append("%s uninstall" % self.uninst)
                        if self.uninst > 1:
                                details[-1] += "s"
                if self.interactive > 0:
                        details.append("%s %s" % (self.interactive,
                                colorize("WARN", "interactive")))
                myoutput.append(", ".join(details))
                if total_installs != 0:
                        myoutput.append(")")
                myoutput.append(", Size of downloads: %s" % format_size(self.totalsize))
                if self.restrict_fetch:
                        myoutput.append("\nFetch Restriction: %s package" % \
                                self.restrict_fetch)
                        if self.restrict_fetch > 1:
                                myoutput.append("s")
                if self.restrict_fetch_satisfied < self.restrict_fetch:
                        myoutput.append(bad(" (%s unsatisfied)") % \
                                (self.restrict_fetch - self.restrict_fetch_satisfied))
                if self.blocks > 0:
                        myoutput.append("\nConflict: %s block" % \
                                self.blocks)
                        if self.blocks > 1:
                                myoutput.append("s")
                        if self.blocks_satisfied < self.blocks:
                                myoutput.append(bad(" (%s unsatisfied)") % \
                                        (self.blocks - self.blocks_satisfied))
                return "".join(myoutput)

class PollConstants(object):

        """
        Provides POLL* constants that are equivalent to those from the
        select module, for use by PollSelectAdapter.
        """

        names = ("POLLIN", "POLLPRI", "POLLOUT", "POLLERR", "POLLHUP", "POLLNVAL")
        v = 1
        for k in names:
                locals()[k] = getattr(select, k, v)
                v *= 2
        del k, v

class PollSelectAdapter(PollConstants):

        """
        Use select to emulate a poll object, for
        systems that don't support poll().
        """

        def __init__(self):
                self._registered = {}
                self._select_args = [[], [], []]

        def register(self, fd, *args):
                """
                Only POLLIN is currently supported!
                """
                if len(args) > 1:
                        raise TypeError(
                                "register expected at most 2 arguments, got " + \
                                repr(1 + len(args)))

                eventmask = PollConstants.POLLIN | \
                        PollConstants.POLLPRI | PollConstants.POLLOUT
                if args:
                        eventmask = args[0]

                self._registered[fd] = eventmask
                self._select_args = None

        def unregister(self, fd):
                self._select_args = None
                del self._registered[fd]

        def poll(self, *args):
                if len(args) > 1:
                        raise TypeError(
                                "poll expected at most 2 arguments, got " + \
                                repr(1 + len(args)))

                timeout = None
                if args:
                        timeout = args[0]

                select_args = self._select_args
                if select_args is None:
                        select_args = [self._registered.keys(), [], []]

                if timeout is not None:
                        select_args = select_args[:]
                        # Translate poll() timeout args to select() timeout args:
                        #
                        #          | units        | value(s) for indefinite block
                        # ---------|--------------|------------------------------
                        #   poll   | milliseconds | omitted, negative, or None
                        # ---------|--------------|------------------------------
                        #   select | seconds      | omitted
                        # ---------|--------------|------------------------------

                        if timeout is not None and timeout < 0:
                                timeout = None
                        if timeout is not None:
                                select_args.append(timeout / 1000)

                select_events = select.select(*select_args)
                poll_events = []
                for fd in select_events[0]:
                        poll_events.append((fd, PollConstants.POLLIN))
                return poll_events

class SequentialTaskQueue(SlotObject):

        __slots__ = ("max_jobs", "running_tasks") + \
                ("_dirty", "_scheduling", "_task_queue")

        def __init__(self, **kwargs):
                SlotObject.__init__(self, **kwargs)
                self._task_queue = deque()
                self.running_tasks = set()
                if self.max_jobs is None:
                        self.max_jobs = 1
                self._dirty = True

        def add(self, task):
                self._task_queue.append(task)
                self._dirty = True

        def addFront(self, task):
                self._task_queue.appendleft(task)
                self._dirty = True

        def schedule(self):

                if not self._dirty:
                        return False

                if not self:
                        return False

                if self._scheduling:
                        # Ignore any recursive schedule() calls triggered via
                        # self._task_exit().
                        return False

                self._scheduling = True

                task_queue = self._task_queue
                running_tasks = self.running_tasks
                max_jobs = self.max_jobs
                state_changed = False

                while task_queue and \
                        (max_jobs is True or len(running_tasks) < max_jobs):
                        task = task_queue.popleft()
                        cancelled = getattr(task, "cancelled", None)
                        if not cancelled:
                                running_tasks.add(task)
                                task.addExitListener(self._task_exit)
                                task.start()
                        state_changed = True

                self._dirty = False
                self._scheduling = False

                return state_changed

        def _task_exit(self, task):
                """
                Since we can always rely on exit listeners being called, the set of
                running tasks is always pruned automatically and there is never any need
                to actively prune it.
                """
                self.running_tasks.remove(task)
                if self._task_queue:
                        self._dirty = True

        def clear(self):
                self._task_queue.clear()
                running_tasks = self.running_tasks
                while running_tasks:
                        task = running_tasks.pop()
                        task.removeExitListener(self._task_exit)
                        task.cancel()
                self._dirty = False

        def __nonzero__(self):
                return bool(self._task_queue or self.running_tasks)

        def __len__(self):
                return len(self._task_queue) + len(self.running_tasks)

_can_poll_device = None

def can_poll_device():
        """
        Test if it's possible to use poll() on a device such as a pty. This
        is known to fail on Darwin.
        @rtype: bool
        @returns: True if poll() on a device succeeds, False otherwise.
        """

        global _can_poll_device
        if _can_poll_device is not None:
                return _can_poll_device

        if not hasattr(select, "poll"):
                _can_poll_device = False
                return _can_poll_device

        try:
                dev_null = open('/dev/null', 'rb')
        except IOError:
                _can_poll_device = False
                return _can_poll_device

        p = select.poll()
        p.register(dev_null.fileno(), PollConstants.POLLIN)

        invalid_request = False
        for f, event in p.poll():
                if event & PollConstants.POLLNVAL:
                        invalid_request = True
                        break
        dev_null.close()

        _can_poll_device = not invalid_request
        return _can_poll_device

def create_poll_instance():
        """
        Create an instance of select.poll, or an instance of
        PollSelectAdapter there is no poll() implementation or
        it is broken somehow.
        """
        if can_poll_device():
                return select.poll()
        return PollSelectAdapter()

class PollScheduler(object):

        class _sched_iface_class(SlotObject):
                __slots__ = ("register", "schedule", "unregister")

        def __init__(self):
                self._max_jobs = 1
                self._max_load = None
                self._jobs = 0
                self._poll_event_queue = []
                self._poll_event_handlers = {}
                self._poll_event_handler_ids = {}
                # Increment id for each new handler.
                self._event_handler_id = 0
                self._poll_obj = create_poll_instance()
                self._scheduling = False

        def _schedule(self):
                """
                Calls _schedule_tasks() and automatically returns early from
                any recursive calls to this method that the _schedule_tasks()
                call might trigger. This makes _schedule() safe to call from
                inside exit listeners.
                """
                if self._scheduling:
                        return False
                self._scheduling = True
                try:
                        return self._schedule_tasks()
                finally:
                        self._scheduling = False

        def _running_job_count(self):
                return self._jobs

        def _can_add_job(self):
                max_jobs = self._max_jobs
                max_load = self._max_load

                if self._max_jobs is not True and \
                        self._running_job_count() >= self._max_jobs:
                        return False

                if max_load is not None and \
                        (max_jobs is True or max_jobs > 1) and \
                        self._running_job_count() >= 1:
                        try:
                                avg1, avg5, avg15 = os.getloadavg()
                        except (AttributeError, OSError), e:
                                writemsg("!!! getloadavg() failed: %s\n" % (e,),
                                        noiselevel=-1)
                                del e
                                return False

                        if avg1 >= max_load:
                                return False

                return True

        def _poll(self, timeout=None):
                """
                All poll() calls pass through here. The poll events
                are added directly to self._poll_event_queue.
                In order to avoid endless blocking, this raises
                StopIteration if timeout is None and there are
                no file descriptors to poll.
                """
                if not self._poll_event_handlers:
                        self._schedule()
                        if timeout is None and \
                                not self._poll_event_handlers:
                                raise StopIteration(
                                        "timeout is None and there are no poll() event handlers")

                # The following error is known to occur with Linux kernel versions
                # less than 2.6.24:
                #
                #   select.error: (4, 'Interrupted system call')
                #
                # This error has been observed after a SIGSTOP, followed by SIGCONT.
                # Treat it similar to EAGAIN if timeout is None, otherwise just return
                # without any events.
                while True:
                        try:
                                self._poll_event_queue.extend(self._poll_obj.poll(timeout))
                                break
                        except select.error, e:
                                writemsg_level("\n!!! select error: %s\n" % (e,),
                                        level=logging.ERROR, noiselevel=-1)
                                del e
                                if timeout is not None:
                                        break

        def _next_poll_event(self, timeout=None):
                """
                Since the _schedule_wait() loop is called by event
                handlers from _poll_loop(), maintain a central event
                queue for both of them to share events from a single
                poll() call. In order to avoid endless blocking, this
                raises StopIteration if timeout is None and there are
                no file descriptors to poll.
                """
                if not self._poll_event_queue:
                        self._poll(timeout)
                return self._poll_event_queue.pop()

        def _poll_loop(self):

                event_handlers = self._poll_event_handlers
                event_handled = False

                try:
                        while event_handlers:
                                f, event = self._next_poll_event()
                                handler, reg_id = event_handlers[f]
                                handler(f, event)
                                event_handled = True
                except StopIteration:
                        event_handled = True

                if not event_handled:
                        raise AssertionError("tight loop")

        def _schedule_yield(self):
                """
                Schedule for a short period of time chosen by the scheduler based
                on internal state. Synchronous tasks should call this periodically
                in order to allow the scheduler to service pending poll events. The
                scheduler will call poll() exactly once, without blocking, and any
                resulting poll events will be serviced.
                """
                event_handlers = self._poll_event_handlers
                events_handled = 0

                if not event_handlers:
                        return bool(events_handled)

                if not self._poll_event_queue:
                        self._poll(0)

                try:
                        while event_handlers and self._poll_event_queue:
                                f, event = self._next_poll_event()
                                handler, reg_id = event_handlers[f]
                                handler(f, event)
                                events_handled += 1
                except StopIteration:
                        events_handled += 1

                return bool(events_handled)

        def _register(self, f, eventmask, handler):
                """
                @rtype: Integer
                @return: A unique registration id, for use in schedule() or
                        unregister() calls.
                """
                if f in self._poll_event_handlers:
                        raise AssertionError("fd %d is already registered" % f)
                self._event_handler_id += 1
                reg_id = self._event_handler_id
                self._poll_event_handler_ids[reg_id] = f
                self._poll_event_handlers[f] = (handler, reg_id)
                self._poll_obj.register(f, eventmask)
                return reg_id

        def _unregister(self, reg_id):
                f = self._poll_event_handler_ids[reg_id]
                self._poll_obj.unregister(f)
                del self._poll_event_handlers[f]
                del self._poll_event_handler_ids[reg_id]

        def _schedule_wait(self, wait_ids):
                """
                Schedule until wait_id is not longer registered
                for poll() events.
                @type wait_id: int
                @param wait_id: a task id to wait for
                """
                event_handlers = self._poll_event_handlers
                handler_ids = self._poll_event_handler_ids
                event_handled = False

                if isinstance(wait_ids, int):
                        wait_ids = frozenset([wait_ids])

                try:
                        while wait_ids.intersection(handler_ids):
                                f, event = self._next_poll_event()
                                handler, reg_id = event_handlers[f]
                                handler(f, event)
                                event_handled = True
                except StopIteration:
                        event_handled = True

                return event_handled

class QueueScheduler(PollScheduler):

        """
        Add instances of SequentialTaskQueue and then call run(). The
        run() method returns when no tasks remain.
        """

        def __init__(self, max_jobs=None, max_load=None):
                PollScheduler.__init__(self)

                if max_jobs is None:
                        max_jobs = 1

                self._max_jobs = max_jobs
                self._max_load = max_load
                self.sched_iface = self._sched_iface_class(
                        register=self._register,
                        schedule=self._schedule_wait,
                        unregister=self._unregister)

                self._queues = []
                self._schedule_listeners = []

        def add(self, q):
                self._queues.append(q)

        def remove(self, q):
                self._queues.remove(q)

        def run(self):

                while self._schedule():
                        self._poll_loop()

                while self._running_job_count():
                        self._poll_loop()

        def _schedule_tasks(self):
                """
                @rtype: bool
                @returns: True if there may be remaining tasks to schedule,
                        False otherwise.
                """
                while self._can_add_job():
                        n = self._max_jobs - self._running_job_count()
                        if n < 1:
                                break

                        if not self._start_next_job(n):
                                return False

                for q in self._queues:
                        if q:
                                return True
                return False

        def _running_job_count(self):
                job_count = 0
                for q in self._queues:
                        job_count += len(q.running_tasks)
                self._jobs = job_count
                return job_count

        def _start_next_job(self, n=1):
                started_count = 0
                for q in self._queues:
                        initial_job_count = len(q.running_tasks)
                        q.schedule()
                        final_job_count = len(q.running_tasks)
                        if final_job_count > initial_job_count:
                                started_count += (final_job_count - initial_job_count)
                        if started_count >= n:
                                break
                return started_count

class TaskScheduler(object):

        """
        A simple way to handle scheduling of AsynchrousTask instances. Simply
        add tasks and call run(). The run() method returns when no tasks remain.
        """

        def __init__(self, max_jobs=None, max_load=None):
                self._queue = SequentialTaskQueue(max_jobs=max_jobs)
                self._scheduler = QueueScheduler(
                        max_jobs=max_jobs, max_load=max_load)
                self.sched_iface = self._scheduler.sched_iface
                self.run = self._scheduler.run
                self._scheduler.add(self._queue)

        def add(self, task):
                self._queue.add(task)

        def run(self):
                self._scheduler.schedule()

class JobStatusDisplay(object):

        _bound_properties = ("curval", "failed", "running")
        _jobs_column_width = 48

        # Don't update the display unless at least this much
        # time has passed, in units of seconds.
        _min_display_latency = 2

        _default_term_codes = {
                'cr'  : '\r',
                'el'  : '\x1b[K',
                'nel' : '\n',
        }

        _termcap_name_map = {
                'carriage_return' : 'cr',
                'clr_eol'         : 'el',
                'newline'         : 'nel',
        }

        def __init__(self, out=sys.stdout, quiet=False):
                object.__setattr__(self, "out", out)
                object.__setattr__(self, "quiet", quiet)
                object.__setattr__(self, "maxval", 0)
                object.__setattr__(self, "merges", 0)
                object.__setattr__(self, "_changed", False)
                object.__setattr__(self, "_displayed", False)
                object.__setattr__(self, "_last_display_time", 0)
                object.__setattr__(self, "width", 80)
                self.reset()

                isatty = hasattr(out, "isatty") and out.isatty()
                object.__setattr__(self, "_isatty", isatty)
                if not isatty or not self._init_term():
                        term_codes = {}
                        for k, capname in self._termcap_name_map.iteritems():
                                term_codes[k] = self._default_term_codes[capname]
                        object.__setattr__(self, "_term_codes", term_codes)

        def _init_term(self):
                """
                Initialize term control codes.
                @rtype: bool
                @returns: True if term codes were successfully initialized,
                        False otherwise.
                """

                term_type = os.environ.get("TERM", "vt100")
                tigetstr = None

                try:
                        import curses
                        try:
                                curses.setupterm(term_type, self.out.fileno())
                                tigetstr = curses.tigetstr
                        except curses.error:
                                pass
                except ImportError:
                        pass

                if tigetstr is None:
                        return False

                term_codes = {}
                for k, capname in self._termcap_name_map.iteritems():
                        code = tigetstr(capname)
                        if code is None:
                                code = self._default_term_codes[capname]
                        term_codes[k] = code
                object.__setattr__(self, "_term_codes", term_codes)
                return True

        def _format_msg(self, msg):
                return ">>> %s" % msg

        def _erase(self):
                self.out.write(
                        self._term_codes['carriage_return'] + \
                        self._term_codes['clr_eol'])
                self.out.flush()
                self._displayed = False

        def _display(self, line):
                self.out.write(line)
                self.out.flush()
                self._displayed = True

        def _update(self, msg):

                out = self.out
                if not self._isatty:
                        out.write(self._format_msg(msg) + self._term_codes['newline'])
                        self.out.flush()
                        self._displayed = True
                        return

                if self._displayed:
                        self._erase()

                self._display(self._format_msg(msg))

        def displayMessage(self, msg):

                was_displayed = self._displayed

                if self._isatty and self._displayed:
                        self._erase()

                self.out.write(self._format_msg(msg) + self._term_codes['newline'])
                self.out.flush()
                self._displayed = False

                if was_displayed:
                        self._changed = True
                        self.display()

        def reset(self):
                self.maxval = 0
                self.merges = 0
                for name in self._bound_properties:
                        object.__setattr__(self, name, 0)

                if self._displayed:
                        self.out.write(self._term_codes['newline'])
                        self.out.flush()
                        self._displayed = False

        def __setattr__(self, name, value):
                old_value = getattr(self, name)
                if value == old_value:
                        return
                object.__setattr__(self, name, value)
                if name in self._bound_properties:
                        self._property_change(name, old_value, value)

        def _property_change(self, name, old_value, new_value):
                self._changed = True
                self.display()

        def _load_avg_str(self):
                try:
                        avg = os.getloadavg()
                except (AttributeError, OSError), e:
                        return str(e)

                max_avg = max(avg)

                if max_avg < 10:
                        digits = 2
                elif max_avg < 100:
                        digits = 1
                else:
                        digits = 0

                return ", ".join(("%%.%df" % digits ) % x for x in avg)

        def display(self):
                """
                Display status on stdout, but only if something has
                changed since the last call.
                """

                if self.quiet:
                        return

                current_time = time.time()
                time_delta = current_time - self._last_display_time
                if self._displayed and \
                        not self._changed:
                        if not self._isatty:
                                return
                        if time_delta < self._min_display_latency:
                                return

                self._last_display_time = current_time
                self._changed = False
                self._display_status()

        def _display_status(self):
                # Don't use len(self._completed_tasks) here since that also
                # can include uninstall tasks.
                curval_str = str(self.curval)
                maxval_str = str(self.maxval)
                running_str = str(self.running)
                failed_str = str(self.failed)
                load_avg_str = self._load_avg_str()

                color_output = StringIO.StringIO()
                plain_output = StringIO.StringIO()
                style_file = portage.output.ConsoleStyleFile(color_output)
                style_file.write_listener = plain_output
                style_writer = portage.output.StyleWriter(file=style_file, maxcol=9999)
                style_writer.style_listener = style_file.new_styles
                f = formatter.AbstractFormatter(style_writer)

                number_style = "INFORM"
                f.add_literal_data("Jobs: ")
                f.push_style(number_style)
                f.add_literal_data(curval_str)
                f.pop_style()
                f.add_literal_data(" of ")
                f.push_style(number_style)
                f.add_literal_data(maxval_str)
                f.pop_style()
                f.add_literal_data(" complete")

                if self.running:
                        f.add_literal_data(", ")
                        f.push_style(number_style)
                        f.add_literal_data(running_str)
                        f.pop_style()
                        f.add_literal_data(" running")

                if self.failed:
                        f.add_literal_data(", ")
                        f.push_style(number_style)
                        f.add_literal_data(failed_str)
                        f.pop_style()
                        f.add_literal_data(" failed")

                padding = self._jobs_column_width - len(plain_output.getvalue())
                if padding > 0:
                        f.add_literal_data(padding * " ")

                f.add_literal_data("Load avg: ")
                f.add_literal_data(load_avg_str)

                # Truncate to fit width, to avoid making the terminal scroll if the
                # line overflows (happens when the load average is large).
                plain_output = plain_output.getvalue()
                if self._isatty and len(plain_output) > self.width:
                        # Use plain_output here since it's easier to truncate
                        # properly than the color output which contains console
                        # color codes.
                        self._update(plain_output[:self.width])
                else:
                        self._update(color_output.getvalue())

                xtermTitle(" ".join(plain_output.split()))

class Scheduler(PollScheduler):

        _opts_ignore_blockers = \
                frozenset(["--buildpkgonly",
                "--fetchonly", "--fetch-all-uri",
                "--nodeps", "--pretend"])

        _opts_no_background = \
                frozenset(["--pretend",
                "--fetchonly", "--fetch-all-uri"])

        _opts_no_restart = frozenset(["--buildpkgonly",
                "--fetchonly", "--fetch-all-uri", "--pretend"])

        _bad_resume_opts = set(["--ask", "--changelog",
                "--resume", "--skipfirst"])

        _fetch_log = "/var/log/emerge-fetch.log"

        class _iface_class(SlotObject):
                __slots__ = ("dblinkEbuildPhase", "dblinkDisplayMerge",
                        "dblinkElog", "fetch", "register", "schedule",
                        "scheduleSetup", "scheduleUnpack", "scheduleYield",
                        "unregister")

        class _fetch_iface_class(SlotObject):
                __slots__ = ("log_file", "schedule")

        _task_queues_class = slot_dict_class(
                ("merge", "jobs", "fetch", "unpack"), prefix="")

        class _build_opts_class(SlotObject):
                __slots__ = ("buildpkg", "buildpkgonly",
                        "fetch_all_uri", "fetchonly", "pretend")

        class _binpkg_opts_class(SlotObject):
                __slots__ = ("fetchonly", "getbinpkg", "pretend")

        class _pkg_count_class(SlotObject):
                __slots__ = ("curval", "maxval")

        class _emerge_log_class(SlotObject):
                __slots__ = ("xterm_titles",)

                def log(self, *pargs, **kwargs):
                        if not self.xterm_titles:
                                # Avoid interference with the scheduler's status display.
                                kwargs.pop("short_msg", None)
                        emergelog(self.xterm_titles, *pargs, **kwargs)

        class _failed_pkg(SlotObject):
                __slots__ = ("build_dir", "build_log", "pkg", "returncode")

        class _ConfigPool(object):
                """Interface for a task to temporarily allocate a config
                instance from a pool. This allows a task to be constructed
                long before the config instance actually becomes needed, like
                when prefetchers are constructed for the whole merge list."""
                __slots__ = ("_root", "_allocate", "_deallocate")
                def __init__(self, root, allocate, deallocate):
                        self._root = root
                        self._allocate = allocate
                        self._deallocate = deallocate
                def allocate(self):
                        return self._allocate(self._root)
                def deallocate(self, settings):
                        self._deallocate(settings)

        class _unknown_internal_error(portage.exception.PortageException):
                """
                Used internally to terminate scheduling. The specific reason for
                the failure should have been dumped to stderr.
                """
                def __init__(self, value=""):
                        portage.exception.PortageException.__init__(self, value)

        def __init__(self, settings, trees, mtimedb, myopts,
                spinner, mergelist, favorites, digraph):
                PollScheduler.__init__(self)
                self.settings = settings
                self.target_root = settings["ROOT"]
                self.trees = trees
                self.myopts = myopts
                self._spinner = spinner
                self._mtimedb = mtimedb
                self._mergelist = mergelist
                self._favorites = favorites
                self._args_set = InternalPackageSet(favorites)
                self._build_opts = self._build_opts_class()
                for k in self._build_opts.__slots__:
                        setattr(self._build_opts, k, "--" + k.replace("_", "-") in myopts)
                self._binpkg_opts = self._binpkg_opts_class()
                for k in self._binpkg_opts.__slots__:
                        setattr(self._binpkg_opts, k, "--" + k.replace("_", "-") in myopts)

                self.curval = 0
                self._logger = self._emerge_log_class()
                self._task_queues = self._task_queues_class()
                for k in self._task_queues.allowed_keys:
                        setattr(self._task_queues, k,
                                SequentialTaskQueue())
                self._status_display = JobStatusDisplay()
                self._max_load = myopts.get("--load-average")
                max_jobs = myopts.get("--jobs")
                if max_jobs is None:
                        max_jobs = 1
                self._set_max_jobs(max_jobs)

                # The root where the currently running
                # portage instance is installed.
                self._running_root = trees["/"]["root_config"]
                self.edebug = 0
                if settings.get("PORTAGE_DEBUG", "") == "1":
                        self.edebug = 1
                self.pkgsettings = {}
                self._config_pool = {}
                self._blocker_db = {}
                for root in trees:
                        self._config_pool[root] = []
                        self._blocker_db[root] = BlockerDB(trees[root]["root_config"])

                fetch_iface = self._fetch_iface_class(log_file=self._fetch_log,
                        schedule=self._schedule_fetch)
                self._sched_iface = self._iface_class(
                        dblinkEbuildPhase=self._dblink_ebuild_phase,
                        dblinkDisplayMerge=self._dblink_display_merge,
                        dblinkElog=self._dblink_elog,
                        fetch=fetch_iface, register=self._register,
                        schedule=self._schedule_wait,
                        scheduleSetup=self._schedule_setup,
                        scheduleUnpack=self._schedule_unpack,
                        scheduleYield=self._schedule_yield,
                        unregister=self._unregister)

                self._prefetchers = weakref.WeakValueDictionary()
                self._pkg_queue = []
                self._completed_tasks = set()

                self._failed_pkgs = []
                self._failed_pkgs_all = []
                self._failed_pkgs_die_msgs = []
                self._post_mod_echo_msgs = []
                self._parallel_fetch = False
                merge_count = len([x for x in mergelist \
                        if isinstance(x, Package) and x.operation == "merge"])
                self._pkg_count = self._pkg_count_class(
                        curval=0, maxval=merge_count)
                self._status_display.maxval = self._pkg_count.maxval

                # The load average takes some time to respond when new
                # jobs are added, so we need to limit the rate of adding
                # new jobs.
                self._job_delay_max = 10
                self._job_delay_factor = 1.0
                self._job_delay_exp = 1.5
                self._previous_job_start_time = None

                self._set_digraph(digraph)

                # This is used to memoize the _choose_pkg() result when
                # no packages can be chosen until one of the existing
                # jobs completes.
                self._choose_pkg_return_early = False

                features = self.settings.features
                if "parallel-fetch" in features and \
                        not ("--pretend" in self.myopts or \
                        "--fetch-all-uri" in self.myopts or \
                        "--fetchonly" in self.myopts):
                        if "distlocks" not in features:
                                portage.writemsg(red("!!!")+"\n", noiselevel=-1)
                                portage.writemsg(red("!!!")+" parallel-fetching " + \
                                        "requires the distlocks feature enabled"+"\n",
                                        noiselevel=-1)
                                portage.writemsg(red("!!!")+" you have it disabled, " + \
                                        "thus parallel-fetching is being disabled"+"\n",
                                        noiselevel=-1)
                                portage.writemsg(red("!!!")+"\n", noiselevel=-1)
                        elif len(mergelist) > 1:
                                self._parallel_fetch = True

                if self._parallel_fetch:
                                # clear out existing fetch log if it exists
                                try:
                                        open(self._fetch_log, 'w')
                                except EnvironmentError:
                                        pass

                self._running_portage = None
                portage_match = self._running_root.trees["vartree"].dbapi.match(
                        portage.const.PORTAGE_PACKAGE_ATOM)
                if portage_match:
                        cpv = portage_match.pop()
                        self._running_portage = self._pkg(cpv, "installed",
                                self._running_root, installed=True)

        def _poll(self, timeout=None):
                self._schedule()
                PollScheduler._poll(self, timeout=timeout)

        def _set_max_jobs(self, max_jobs):
                self._max_jobs = max_jobs
                self._task_queues.jobs.max_jobs = max_jobs

        def _background_mode(self):
                """
                Check if background mode is enabled and adjust states as necessary.

                @rtype: bool
                @returns: True if background mode is enabled, False otherwise.
                """
                background = (self._max_jobs is True or \
                        self._max_jobs > 1 or "--quiet" in self.myopts) and \
                        not bool(self._opts_no_background.intersection(self.myopts))

                if background:
                        interactive_tasks = self._get_interactive_tasks()
                        if interactive_tasks:
                                background = False
                                writemsg_level(">>> Sending package output to stdio due " + \
                                        "to interactive package(s):\n",
                                        level=logging.INFO, noiselevel=-1)
                                msg = [""]
                                for pkg in interactive_tasks:
                                        pkg_str = "  " + colorize("INFORM", str(pkg.cpv))
                                        if pkg.root != "/":
                                                pkg_str += " for " + pkg.root
                                        msg.append(pkg_str)
                                msg.append("")
                                writemsg_level("".join("%s\n" % (l,) for l in msg),
                                        level=logging.INFO, noiselevel=-1)
                                if self._max_jobs is True or self._max_jobs > 1:
                                        self._set_max_jobs(1)
                                        writemsg_level(">>> Setting --jobs=1 due " + \
                                                "to the above interactive package(s)\n",
                                                level=logging.INFO, noiselevel=-1)

                self._status_display.quiet = \
                        not background or \
                        ("--quiet" in self.myopts and \
                        "--verbose" not in self.myopts)

                self._logger.xterm_titles = \
                        "notitles" not in self.settings.features and \
                        self._status_display.quiet

                return background

        def _get_interactive_tasks(self):
                from portage import flatten
                from portage.dep import use_reduce, paren_reduce
                interactive_tasks = []
                for task in self._mergelist:
                        if not (isinstance(task, Package) and \
                                task.operation == "merge"):
                                continue
                        try:
                                properties = flatten(use_reduce(paren_reduce(
                                        task.metadata["PROPERTIES"]), uselist=task.use.enabled))
                        except portage.exception.InvalidDependString, e:
                                show_invalid_depstring_notice(task,
                                        task.metadata["PROPERTIES"], str(e))
                                raise self._unknown_internal_error()
                        if "interactive" in properties:
                                interactive_tasks.append(task)
                return interactive_tasks

        def _set_digraph(self, digraph):
                if "--nodeps" in self.myopts or \
                        (self._max_jobs is not True and self._max_jobs < 2):
                        # save some memory
                        self._digraph = None
                        return

                self._digraph = digraph
                self._prune_digraph()

        def _prune_digraph(self):
                """
                Prune any root nodes that are irrelevant.
                """

                graph = self._digraph
                completed_tasks = self._completed_tasks
                removed_nodes = set()
                while True:
                        for node in graph.root_nodes():
                                if not isinstance(node, Package) or \
                                        (node.installed and node.operation == "nomerge") or \
                                        node.onlydeps or \
                                        node in completed_tasks:
                                        removed_nodes.add(node)
                        if removed_nodes:
                                graph.difference_update(removed_nodes)
                        if not removed_nodes:
                                break
                        removed_nodes.clear()

        class _pkg_failure(portage.exception.PortageException):
                """
                An instance of this class is raised by unmerge() when
                an uninstallation fails.
                """
                status = 1
                def __init__(self, *pargs):
                        portage.exception.PortageException.__init__(self, pargs)
                        if pargs:
                                self.status = pargs[0]

        def _schedule_fetch(self, fetcher):
                """
                Schedule a fetcher on the fetch queue, in order to
                serialize access to the fetch log.
                """
                self._task_queues.fetch.addFront(fetcher)

        def _schedule_setup(self, setup_phase):
                """
                Schedule a setup phase on the merge queue, in order to
                serialize unsandboxed access to the live filesystem.
                """
                self._task_queues.merge.addFront(setup_phase)
                self._schedule()

        def _schedule_unpack(self, unpack_phase):
                """
                Schedule an unpack phase on the unpack queue, in order
                to serialize $DISTDIR access for live ebuilds.
                """
                self._task_queues.unpack.add(unpack_phase)

        def _find_blockers(self, new_pkg):
                """
                Returns a callable which should be called only when
                the vdb lock has been acquired.
                """
                def get_blockers():
                        return self._find_blockers_with_lock(new_pkg, acquire_lock=0)
                return get_blockers

        def _find_blockers_with_lock(self, new_pkg, acquire_lock=0):
                if self._opts_ignore_blockers.intersection(self.myopts):
                        return None

                # Call gc.collect() here to avoid heap overflow that
                # triggers 'Cannot allocate memory' errors (reported
                # with python-2.5).
                import gc
                gc.collect()

                blocker_db = self._blocker_db[new_pkg.root]

                blocker_dblinks = []
                for blocking_pkg in blocker_db.findInstalledBlockers(
                        new_pkg, acquire_lock=acquire_lock):
                        if new_pkg.slot_atom == blocking_pkg.slot_atom:
                                continue
                        if new_pkg.cpv == blocking_pkg.cpv:
                                continue
                        blocker_dblinks.append(portage.dblink(
                                blocking_pkg.category, blocking_pkg.pf, blocking_pkg.root,
                                self.pkgsettings[blocking_pkg.root], treetype="vartree",
                                vartree=self.trees[blocking_pkg.root]["vartree"]))

                gc.collect()

                return blocker_dblinks

        def _dblink_pkg(self, pkg_dblink):
                cpv = pkg_dblink.mycpv
                type_name = RootConfig.tree_pkg_map[pkg_dblink.treetype]
                root_config = self.trees[pkg_dblink.myroot]["root_config"]
                installed = type_name == "installed"
                return self._pkg(cpv, type_name, root_config, installed=installed)

        def _append_to_log_path(self, log_path, msg):
                f = open(log_path, 'a')
                try:
                        f.write(msg)
                finally:
                        f.close()

        def _dblink_elog(self, pkg_dblink, phase, func, msgs):

                log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
                log_file = None
                out = sys.stdout
                background = self._background

                if background and log_path is not None:
                        log_file = open(log_path, 'a')
                        out = log_file

                try:
                        for msg in msgs:
                                func(msg, phase=phase, key=pkg_dblink.mycpv, out=out)
                finally:
                        if log_file is not None:
                                log_file.close()

        def _dblink_display_merge(self, pkg_dblink, msg, level=0, noiselevel=0):
                log_path = pkg_dblink.settings.get("PORTAGE_LOG_FILE")
                background = self._background

                if log_path is None:
                        if not (background and level < logging.WARN):
                                portage.util.writemsg_level(msg,
                                        level=level, noiselevel=noiselevel)
                else:
                        if not background:
                                portage.util.writemsg_level(msg,
                                        level=level, noiselevel=noiselevel)
                        self._append_to_log_path(log_path, msg)

        def _dblink_ebuild_phase(self,
                pkg_dblink, pkg_dbapi, ebuild_path, phase):
                """
                Using this callback for merge phases allows the scheduler
                to run while these phases execute asynchronously, and allows
                the scheduler control output handling.
                """

                scheduler = self._sched_iface
                settings = pkg_dblink.settings
                pkg = self._dblink_pkg(pkg_dblink)
                background = self._background
                log_path = settings.get("PORTAGE_LOG_FILE")

                ebuild_phase = EbuildPhase(background=background,
                        pkg=pkg, phase=phase, scheduler=scheduler,
                        settings=settings, tree=pkg_dblink.treetype)
                ebuild_phase.start()
                ebuild_phase.wait()

                return ebuild_phase.returncode

        def _check_manifests(self):
                # Verify all the manifests now so that the user is notified of failure
                # as soon as possible.
                if "strict" not in self.settings.features or \
                        "--fetchonly" in self.myopts or \
                        "--fetch-all-uri" in self.myopts:
                        return os.EX_OK

                shown_verifying_msg = False
                quiet_settings = {}
                for myroot, pkgsettings in self.pkgsettings.iteritems():
                        quiet_config = portage.config(clone=pkgsettings)
                        quiet_config["PORTAGE_QUIET"] = "1"
                        quiet_config.backup_changes("PORTAGE_QUIET")
                        quiet_settings[myroot] = quiet_config
                        del quiet_config

                for x in self._mergelist:
                        if not isinstance(x, Package) or \
                                x.type_name != "ebuild":
                                continue

                        if not shown_verifying_msg:
                                shown_verifying_msg = True
                                self._status_msg("Verifying ebuild manifests")

                        root_config = x.root_config
                        portdb = root_config.trees["porttree"].dbapi
                        quiet_config = quiet_settings[root_config.root]
                        quiet_config["O"] = os.path.dirname(portdb.findname(x.cpv))
                        if not portage.digestcheck([], quiet_config, strict=True):
                                return 1

                return os.EX_OK

        def _add_prefetchers(self):

                if not self._parallel_fetch:
                        return

                if self._parallel_fetch:
                        self._status_msg("Starting parallel fetch")

                        prefetchers = self._prefetchers
                        getbinpkg = "--getbinpkg" in self.myopts

                        # In order to avoid "waiting for lock" messages
                        # at the beginning, which annoy users, never
                        # spawn a prefetcher for the first package.
                        for pkg in self._mergelist[1:]:
                                prefetcher = self._create_prefetcher(pkg)
                                if prefetcher is not None:
                                        self._task_queues.fetch.add(prefetcher)
                                        prefetchers[pkg] = prefetcher

        def _create_prefetcher(self, pkg):
                """
                @return: a prefetcher, or None if not applicable
                """
                prefetcher = None

                if not isinstance(pkg, Package):
                        pass

                elif pkg.type_name == "ebuild":

                        prefetcher = EbuildFetcher(background=True,
                                config_pool=self._ConfigPool(pkg.root,
                                self._allocate_config, self._deallocate_config),
                                fetchonly=1, logfile=self._fetch_log,
                                pkg=pkg, prefetch=True, scheduler=self._sched_iface)

                elif pkg.type_name == "binary" and \
                        "--getbinpkg" in self.myopts and \
                        pkg.root_config.trees["bintree"].isremote(pkg.cpv):

                        prefetcher = BinpkgFetcher(background=True,
                                logfile=self._fetch_log, pkg=pkg,
                                scheduler=self._sched_iface)

                return prefetcher

        def _is_restart_scheduled(self):
                """
                Check if the merge list contains a replacement
                for the current running instance, that will result
                in restart after merge.
                @rtype: bool
                @returns: True if a restart is scheduled, False otherwise.
                """
                if self._opts_no_restart.intersection(self.myopts):
                        return False

                mergelist = self._mergelist

                for i, pkg in enumerate(mergelist):
                        if self._is_restart_necessary(pkg) and \
                                i != len(mergelist) - 1:
                                return True

                return False

        def _is_restart_necessary(self, pkg):
                """
                @return: True if merging the given package
                        requires restart, False otherwise.
                """

                # Figure out if we need a restart.
                if pkg.root == self._running_root.root and \
                        portage.match_from_list(
                        portage.const.PORTAGE_PACKAGE_ATOM, [pkg]):
                        if self._running_portage:
                                return cmp(pkg, self._running_portage) != 0
                        return True
                return False

        def _restart_if_necessary(self, pkg):
                """
                Use execv() to restart emerge. This happens
                if portage upgrades itself and there are
                remaining packages in the list.
                """

                if self._opts_no_restart.intersection(self.myopts):
                        return

                if not self._is_restart_necessary(pkg):
                        return

                if pkg == self._mergelist[-1]:
                        return

                self._main_loop_cleanup()

                logger = self._logger
                pkg_count = self._pkg_count
                mtimedb = self._mtimedb
                bad_resume_opts = self._bad_resume_opts

                logger.log(" ::: completed emerge (%s of %s) %s to %s" % \
                        (pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg.root))

                logger.log(" *** RESTARTING " + \
                        "emerge via exec() after change of " + \
                        "portage version.")

                mtimedb["resume"]["mergelist"].remove(list(pkg))
                mtimedb.commit()
                portage.run_exitfuncs()
                mynewargv = [sys.argv[0], "--resume"]
                resume_opts = self.myopts.copy()
                # For automatic resume, we need to prevent
                # any of bad_resume_opts from leaking in
                # via EMERGE_DEFAULT_OPTS.
                resume_opts["--ignore-default-opts"] = True
                for myopt, myarg in resume_opts.iteritems():
                        if myopt not in bad_resume_opts:
                                if myarg is True:
                                        mynewargv.append(myopt)
                                else:
                                        mynewargv.append(myopt +"="+ str(myarg))
                # priority only needs to be adjusted on the first run
                os.environ["PORTAGE_NICENESS"] = "0"
                os.execv(mynewargv[0], mynewargv)

        def merge(self):

                if "--resume" in self.myopts:
                        # We're resuming.
                        portage.writemsg_stdout(
                                colorize("GOOD", "*** Resuming merge...\n"), noiselevel=-1)
                        self._logger.log(" *** Resuming merge...")

                self._save_resume_list()

                try:
                        self._background = self._background_mode()
                except self._unknown_internal_error:
                        return 1

                for root in self.trees:
                        root_config = self.trees[root]["root_config"]

                        # Even for --pretend --fetch mode, PORTAGE_TMPDIR is required
                        # since it might spawn pkg_nofetch which requires PORTAGE_BUILDDIR
                        # for ensuring sane $PWD (bug #239560) and storing elog messages.
                        tmpdir = root_config.settings.get("PORTAGE_TMPDIR", "")
                        if not tmpdir or not os.path.isdir(tmpdir):
                                msg = "The directory specified in your " + \
                                        "PORTAGE_TMPDIR variable, '%s', " % tmpdir + \
                                "does not exist. Please create this " + \
                                "directory or correct your PORTAGE_TMPDIR setting."
                                msg = textwrap.wrap(msg, 70)
                                out = portage.output.EOutput()
                                for l in msg:
                                        out.eerror(l)
                                return 1

                        if self._background:
                                root_config.settings.unlock()
                                root_config.settings["PORTAGE_BACKGROUND"] = "1"
                                root_config.settings.backup_changes("PORTAGE_BACKGROUND")
                                root_config.settings.lock()

                        self.pkgsettings[root] = portage.config(
                                clone=root_config.settings)

                rval = self._check_manifests()
                if rval != os.EX_OK:
                        return rval

                keep_going = "--keep-going" in self.myopts
                fetchonly = self._build_opts.fetchonly
                mtimedb = self._mtimedb
                failed_pkgs = self._failed_pkgs

                while True:
                        rval = self._merge()
                        if rval == os.EX_OK or fetchonly or not keep_going:
                                break
                        if "resume" not in mtimedb:
                                break
                        mergelist = self._mtimedb["resume"].get("mergelist")
                        if not mergelist:
                                break

                        if not failed_pkgs:
                                break

                        for failed_pkg in failed_pkgs:
                                mergelist.remove(list(failed_pkg.pkg))

                        self._failed_pkgs_all.extend(failed_pkgs)
                        del failed_pkgs[:]

                        if not mergelist:
                                break

                        if not self._calc_resume_list():
                                break

                        clear_caches(self.trees)
                        if not self._mergelist:
                                break

                        self._save_resume_list()
                        self._pkg_count.curval = 0
                        self._pkg_count.maxval = len([x for x in self._mergelist \
                                if isinstance(x, Package) and x.operation == "merge"])
                        self._status_display.maxval = self._pkg_count.maxval

                self._logger.log(" *** Finished. Cleaning up...")

                if failed_pkgs:
                        self._failed_pkgs_all.extend(failed_pkgs)
                        del failed_pkgs[:]

                background = self._background
                failure_log_shown = False
                if background and len(self._failed_pkgs_all) == 1:
                        # If only one package failed then just show it's
                        # whole log for easy viewing.
                        failed_pkg = self._failed_pkgs_all[-1]
                        build_dir = failed_pkg.build_dir
                        log_file = None

                        log_paths = [failed_pkg.build_log]

                        log_path = self._locate_failure_log(failed_pkg)
                        if log_path is not None:
                                try:
                                        log_file = open(log_path, 'rb')
                                except IOError:
                                        pass

                        if log_file is not None:
                                try:
                                        for line in log_file:
                                                writemsg_level(line, noiselevel=-1)
                                finally:
                                        log_file.close()
                                failure_log_shown = True

                # Dump mod_echo output now since it tends to flood the terminal.
                # This allows us to avoid having more important output, generated
                # later, from being swept away by the mod_echo output.
                mod_echo_output =  _flush_elog_mod_echo()

                if background and not failure_log_shown and \
                        self._failed_pkgs_all and \
                        self._failed_pkgs_die_msgs and \
                        not mod_echo_output:

                        printer = portage.output.EOutput()
                        for mysettings, key, logentries in self._failed_pkgs_die_msgs:
                                root_msg = ""
                                if mysettings["ROOT"] != "/":
                                        root_msg = " merged to %s" % mysettings["ROOT"]
                                print
                                printer.einfo("Error messages for package %s%s:" % \
                                        (colorize("INFORM", key), root_msg))
                                print
                                for phase in portage.const.EBUILD_PHASES:
                                        if phase not in logentries:
                                                continue
                                        for msgtype, msgcontent in logentries[phase]:
                                                if isinstance(msgcontent, basestring):
                                                        msgcontent = [msgcontent]
                                                for line in msgcontent:
                                                        printer.eerror(line.strip("\n"))

                if self._post_mod_echo_msgs:
                        for msg in self._post_mod_echo_msgs:
                                msg()

                if len(self._failed_pkgs_all) > 1:
                        msg = "The following packages have " + \
                                "failed to build or install:"
                        prefix = bad(" * ")
                        writemsg(prefix + "\n", noiselevel=-1)
                        from textwrap import wrap
                        for line in wrap(msg, 72):
                                writemsg("%s%s\n" % (prefix, line), noiselevel=-1)
                        writemsg(prefix + "\n", noiselevel=-1)
                        for failed_pkg in self._failed_pkgs_all:
                                writemsg("%s\t%s\n" % (prefix,
                                        colorize("INFORM", str(failed_pkg.pkg))),
                                        noiselevel=-1)
                        writemsg(prefix + "\n", noiselevel=-1)

                return rval

        def _elog_listener(self, mysettings, key, logentries, fulltext):
                errors = portage.elog.filter_loglevels(logentries, ["ERROR"])
                if errors:
                        self._failed_pkgs_die_msgs.append(
                                (mysettings, key, errors))

        def _locate_failure_log(self, failed_pkg):

                build_dir = failed_pkg.build_dir
                log_file = None

                log_paths = [failed_pkg.build_log]

                for log_path in log_paths:
                        if not log_path:
                                continue

                        try:
                                log_size = os.stat(log_path).st_size
                        except OSError:
                                continue

                        if log_size == 0:
                                continue

                        return log_path

                return None

        def _add_packages(self):
                pkg_queue = self._pkg_queue
                for pkg in self._mergelist:
                        if isinstance(pkg, Package):
                                pkg_queue.append(pkg)
                        elif isinstance(pkg, Blocker):
                                pass

        def _merge_exit(self, merge):
                self._do_merge_exit(merge)
                self._deallocate_config(merge.merge.settings)
                if merge.returncode == os.EX_OK and \
                        not merge.merge.pkg.installed:
                        self._status_display.curval += 1
                self._status_display.merges = len(self._task_queues.merge)
                self._schedule()

        def _do_merge_exit(self, merge):
                pkg = merge.merge.pkg
                if merge.returncode != os.EX_OK:
                        settings = merge.merge.settings
                        build_dir = settings.get("PORTAGE_BUILDDIR")
                        build_log = settings.get("PORTAGE_LOG_FILE")

                        self._failed_pkgs.append(self._failed_pkg(
                                build_dir=build_dir, build_log=build_log,
                                pkg=pkg,
                                returncode=merge.returncode))
                        self._failed_pkg_msg(self._failed_pkgs[-1], "install", "to")

                        self._status_display.failed = len(self._failed_pkgs)
                        return

                self._task_complete(pkg)
                pkg_to_replace = merge.merge.pkg_to_replace
                if pkg_to_replace is not None:
                        # When a package is replaced, mark it's uninstall
                        # task complete (if any).
                        uninst_hash_key = \
                                ("installed", pkg.root, pkg_to_replace.cpv, "uninstall")
                        self._task_complete(uninst_hash_key)

                if pkg.installed:
                        return

                self._restart_if_necessary(pkg)

                # Call mtimedb.commit() after each merge so that
                # --resume still works after being interrupted
                # by reboot, sigkill or similar.
                mtimedb = self._mtimedb
                mtimedb["resume"]["mergelist"].remove(list(pkg))
                if not mtimedb["resume"]["mergelist"]:
                        del mtimedb["resume"]
                mtimedb.commit()

        def _build_exit(self, build):
                if build.returncode == os.EX_OK:
                        self.curval += 1
                        merge = PackageMerge(merge=build)
                        merge.addExitListener(self._merge_exit)
                        self._task_queues.merge.add(merge)
                        self._status_display.merges = len(self._task_queues.merge)
                else:
                        settings = build.settings
                        build_dir = settings.get("PORTAGE_BUILDDIR")
                        build_log = settings.get("PORTAGE_LOG_FILE")

                        self._failed_pkgs.append(self._failed_pkg(
                                build_dir=build_dir, build_log=build_log,
                                pkg=build.pkg,
                                returncode=build.returncode))
                        self._failed_pkg_msg(self._failed_pkgs[-1], "emerge", "for")

                        self._status_display.failed = len(self._failed_pkgs)
                        self._deallocate_config(build.settings)
                self._jobs -= 1
                self._status_display.running = self._jobs
                self._schedule()

        def _extract_exit(self, build):
                self._build_exit(build)

        def _task_complete(self, pkg):
                self._completed_tasks.add(pkg)
                self._choose_pkg_return_early = False

        def _merge(self):

                self._add_prefetchers()
                self._add_packages()
                pkg_queue = self._pkg_queue
                failed_pkgs = self._failed_pkgs
                portage.locks._quiet = self._background
                portage.elog._emerge_elog_listener = self._elog_listener
                rval = os.EX_OK

                try:
                        self._main_loop()
                finally:
                        self._main_loop_cleanup()
                        portage.locks._quiet = False
                        portage.elog._emerge_elog_listener = None
                        if failed_pkgs:
                                rval = failed_pkgs[-1].returncode

                return rval

        def _main_loop_cleanup(self):
                del self._pkg_queue[:]
                self._completed_tasks.clear()
                self._choose_pkg_return_early = False
                self._status_display.reset()
                self._digraph = None
                self._task_queues.fetch.clear()

        def _choose_pkg(self):
                """
                Choose a task that has all it's dependencies satisfied.
                """

                if self._choose_pkg_return_early:
                        return None

                if self._digraph is None:
                        if (self._jobs or self._task_queues.merge) and \
                                not ("--nodeps" in self.myopts and \
                                (self._max_jobs is True or self._max_jobs > 1)):
                                self._choose_pkg_return_early = True
                                return None
                        return self._pkg_queue.pop(0)

                if not (self._jobs or self._task_queues.merge):
                        return self._pkg_queue.pop(0)

                self._prune_digraph()

                chosen_pkg = None
                later = set(self._pkg_queue)
                for pkg in self._pkg_queue:
                        later.remove(pkg)
                        if not self._dependent_on_scheduled_merges(pkg, later):
                                chosen_pkg = pkg
                                break

                if chosen_pkg is not None:
                        self._pkg_queue.remove(chosen_pkg)

                if chosen_pkg is None:
                        # There's no point in searching for a package to
                        # choose until at least one of the existing jobs
                        # completes.
                        self._choose_pkg_return_early = True

                return chosen_pkg

        def _dependent_on_scheduled_merges(self, pkg, later):
                """
                Traverse the subgraph of the given packages deep dependencies
                to see if it contains any scheduled merges.
                @param pkg: a package to check dependencies for
                @type pkg: Package
                @param later: packages for which dependence should be ignored
                        since they will be merged later than pkg anyway and therefore
                        delaying the merge of pkg will not result in a more optimal
                        merge order
                @type later: set
                @rtype: bool
                @returns: True if the package is dependent, False otherwise.
                """

                graph = self._digraph
                completed_tasks = self._completed_tasks

                dependent = False
                traversed_nodes = set([pkg])
                direct_deps = graph.child_nodes(pkg)
                node_stack = direct_deps
                direct_deps = frozenset(direct_deps)
                while node_stack:
                        node = node_stack.pop()
                        if node in traversed_nodes:
                                continue
                        traversed_nodes.add(node)
                        if not ((node.installed and node.operation == "nomerge") or \
                                (node.operation == "uninstall" and \
                                node not in direct_deps) or \
                                node in completed_tasks or \
                                node in later):
                                dependent = True
                                break
                        node_stack.extend(graph.child_nodes(node))

                return dependent

        def _allocate_config(self, root):
                """
                Allocate a unique config instance for a task in order
                to prevent interference between parallel tasks.
                """
                if self._config_pool[root]:
                        temp_settings = self._config_pool[root].pop()
                else:
                        temp_settings = portage.config(clone=self.pkgsettings[root])
                # Since config.setcpv() isn't guaranteed to call config.reset() due to
                # performance reasons, call it here to make sure all settings from the
                # previous package get flushed out (such as PORTAGE_LOG_FILE).
                temp_settings.reload()
                temp_settings.reset()
                return temp_settings

        def _deallocate_config(self, settings):
                self._config_pool[settings["ROOT"]].append(settings)

        def _main_loop(self):

                # Only allow 1 job max if a restart is scheduled
                # due to portage update.
                if self._is_restart_scheduled() or \
                        self._opts_no_background.intersection(self.myopts):
                        self._set_max_jobs(1)

                merge_queue = self._task_queues.merge

                while self._schedule():
                        if self._poll_event_handlers:
                                self._poll_loop()

                while True:
                        self._schedule()
                        if not (self._jobs or merge_queue):
                                break
                        if self._poll_event_handlers:
                                self._poll_loop()

        def _keep_scheduling(self):
                return bool(self._pkg_queue and \
                        not (self._failed_pkgs and not self._build_opts.fetchonly))

        def _schedule_tasks(self):
                self._schedule_tasks_imp()
                self._status_display.display()

                state_change = 0
                for q in self._task_queues.values():
                        if q.schedule():
                                state_change += 1

                # Cancel prefetchers if they're the only reason
                # the main poll loop is still running.
                if self._failed_pkgs and not self._build_opts.fetchonly and \
                        not (self._jobs or self._task_queues.merge) and \
                        self._task_queues.fetch:
                        self._task_queues.fetch.clear()
                        state_change += 1

                if state_change:
                        self._schedule_tasks_imp()
                        self._status_display.display()

                return self._keep_scheduling()

        def _job_delay(self):
                """
                @rtype: bool
                @returns: True if job scheduling should be delayed, False otherwise.
                """

                if self._jobs and self._max_load is not None:

                        current_time = time.time()

                        delay = self._job_delay_factor * self._jobs ** self._job_delay_exp
                        if delay > self._job_delay_max:
                                delay = self._job_delay_max
                        if (current_time - self._previous_job_start_time) < delay:
                                return True

                return False

        def _schedule_tasks_imp(self):
                """
                @rtype: bool
                @returns: True if state changed, False otherwise.
                """

                state_change = 0

                while True:

                        if not self._keep_scheduling():
                                return bool(state_change)

                        if self._choose_pkg_return_early or \
                                not self._can_add_job() or \
                                self._job_delay():
                                return bool(state_change)

                        pkg = self._choose_pkg()
                        if pkg is None:
                                return bool(state_change)

                        state_change += 1

                        if not pkg.installed:
                                self._pkg_count.curval += 1

                        task = self._task(pkg)

                        if pkg.installed:
                                merge = PackageMerge(merge=task)
                                merge.addExitListener(self._merge_exit)
                                self._task_queues.merge.add(merge)

                        elif pkg.built:
                                self._jobs += 1
                                self._previous_job_start_time = time.time()
                                self._status_display.running = self._jobs
                                task.addExitListener(self._extract_exit)
                                self._task_queues.jobs.add(task)

                        else:
                                self._jobs += 1
                                self._previous_job_start_time = time.time()
                                self._status_display.running = self._jobs
                                task.addExitListener(self._build_exit)
                                self._task_queues.jobs.add(task)

                return bool(state_change)

        def _task(self, pkg):

                pkg_to_replace = None
                if pkg.operation != "uninstall":
                        vardb = pkg.root_config.trees["vartree"].dbapi
                        previous_cpv = vardb.match(pkg.slot_atom)
                        if previous_cpv:
                                previous_cpv = previous_cpv.pop()
                                pkg_to_replace = self._pkg(previous_cpv,
                                        "installed", pkg.root_config, installed=True)

                task = MergeListItem(args_set=self._args_set,
                        background=self._background, binpkg_opts=self._binpkg_opts,
                        build_opts=self._build_opts,
                        config_pool=self._ConfigPool(pkg.root,
                        self._allocate_config, self._deallocate_config),
                        emerge_opts=self.myopts,
                        find_blockers=self._find_blockers(pkg), logger=self._logger,
                        mtimedb=self._mtimedb, pkg=pkg, pkg_count=self._pkg_count.copy(),
                        pkg_to_replace=pkg_to_replace,
                        prefetcher=self._prefetchers.get(pkg),
                        scheduler=self._sched_iface,
                        settings=self._allocate_config(pkg.root),
                        statusMessage=self._status_msg,
                        world_atom=self._world_atom)

                return task

        def _failed_pkg_msg(self, failed_pkg, action, preposition):
                pkg = failed_pkg.pkg
                msg = "%s to %s %s" % \
                        (bad("Failed"), action, colorize("INFORM", pkg.cpv))
                if pkg.root != "/":
                        msg += " %s %s" % (preposition, pkg.root)

                log_path = self._locate_failure_log(failed_pkg)
                if log_path is not None:
                        msg += ", Log file:"
                self._status_msg(msg)

                if log_path is not None:
                        self._status_msg(" '%s'" % (colorize("INFORM", log_path),))

        def _status_msg(self, msg):
                """
                Display a brief status message (no newlines) in the status display.
                This is called by tasks to provide feedback to the user. This
                delegates the resposibility of generating \r and \n control characters,
                to guarantee that lines are created or erased when necessary and
                appropriate.

                @type msg: str
                @param msg: a brief status message (no newlines allowed)
                """
                if not self._background:
                        writemsg_level("\n")
                self._status_display.displayMessage(msg)

        def _save_resume_list(self):
                """
                Do this before verifying the ebuild Manifests since it might
                be possible for the user to use --resume --skipfirst get past
                a non-essential package with a broken digest.
                """
                mtimedb = self._mtimedb
                mtimedb["resume"]["mergelist"] = [list(x) \
                        for x in self._mergelist \
                        if isinstance(x, Package) and x.operation == "merge"]

                mtimedb.commit()

        def _calc_resume_list(self):
                """
                Use the current resume list to calculate a new one,
                dropping any packages with unsatisfied deps.
                @rtype: bool
                @returns: True if successful, False otherwise.
                """
                print colorize("GOOD", "*** Resuming merge...")

                if self._show_list():
                        if "--tree" in self.myopts:
                                portage.writemsg_stdout("\n" + \
                                        darkgreen("These are the packages that " + \
                                        "would be merged, in reverse order:\n\n"))

                        else:
                                portage.writemsg_stdout("\n" + \
                                        darkgreen("These are the packages that " + \
                                        "would be merged, in order:\n\n"))

                show_spinner = "--quiet" not in self.myopts and \
                        "--nodeps" not in self.myopts

                if show_spinner:
                        print "Calculating dependencies  ",

                myparams = create_depgraph_params(self.myopts, None)
                success = False
                e = None
                try:
                        success, mydepgraph, dropped_tasks = resume_depgraph(
                                self.settings, self.trees, self._mtimedb, self.myopts,
                                myparams, self._spinner, skip_unsatisfied=True)
                except depgraph.UnsatisfiedResumeDep, e:
                        mydepgraph = e.depgraph
                        dropped_tasks = set()

                if show_spinner:
                        print "\b\b... done!"

                if e is not None:
                        def unsatisfied_resume_dep_msg():
                                mydepgraph.display_problems()
                                out = portage.output.EOutput()
                                out.eerror("One or more packages are either masked or " + \
                                        "have missing dependencies:")
                                out.eerror("")
                                indent = "  "
                                show_parents = set()
                                for dep in e.value:
                                        if dep.parent in show_parents:
                                                continue
                                        show_parents.add(dep.parent)
                                        if dep.atom is None:
                                                out.eerror(indent + "Masked package:")
                                                out.eerror(2 * indent + str(dep.parent))
                                                out.eerror("")
                                        else:
                                                out.eerror(indent + str(dep.atom) + " pulled in by:")
                                                out.eerror(2 * indent + str(dep.parent))
                                                out.eerror("")
                                msg = "The resume list contains packages " + \
                                        "that are either masked or have " + \
                                        "unsatisfied dependencies. " + \
                                        "Please restart/continue " + \
                                        "the operation manually, or use --skipfirst " + \
                                        "to skip the first package in the list and " + \
                                        "any other packages that may be " + \
                                        "masked or have missing dependencies."
                                for line in textwrap.wrap(msg, 72):
                                        out.eerror(line)
                        self._post_mod_echo_msgs.append(unsatisfied_resume_dep_msg)
                        return False

                if success and self._show_list():
                        mylist = mydepgraph.altlist()
                        if mylist:
                                if "--tree" in self.myopts:
                                        mylist.reverse()
                                mydepgraph.display(mylist, favorites=self._favorites)

                if not success:
                        self._post_mod_echo_msgs.append(mydepgraph.display_problems)
                        return False
                mydepgraph.display_problems()

                mylist = mydepgraph.altlist()
                mydepgraph.break_refs(mylist)
                mydepgraph.break_refs(dropped_tasks)
                self._mergelist = mylist
                self._set_digraph(mydepgraph.schedulerGraph())

                msg_width = 75
                for task in dropped_tasks:
                        if not (isinstance(task, Package) and task.operation == "merge"):
                                continue
                        pkg = task
                        msg = "emerge --keep-going:" + \
                                " %s" % (pkg.cpv,)
                        if pkg.root != "/":
                                msg += " for %s" % (pkg.root,)
                        msg += " dropped due to unsatisfied dependency."
                        for line in textwrap.wrap(msg, msg_width):
                                eerror(line, phase="other", key=pkg.cpv)
                        settings = self.pkgsettings[pkg.root]
                        # Ensure that log collection from $T is disabled inside
                        # elog_process(), since any logs that might exist are
                        # not valid here.
                        settings.pop("T", None)
                        portage.elog.elog_process(pkg.cpv, settings)
                        self._failed_pkgs_all.append(self._failed_pkg(pkg=pkg))

                return True

        def _show_list(self):
                myopts = self.myopts
                if "--quiet" not in myopts and \
                        ("--ask" in myopts or "--tree" in myopts or \
                        "--verbose" in myopts):
                        return True
                return False

        def _world_atom(self, pkg):
                """
                Add the package to the world file, but only if
                it's supposed to be added. Otherwise, do nothing.
                """

                if set(("--buildpkgonly", "--fetchonly",
                        "--fetch-all-uri",
                        "--oneshot", "--onlydeps",
                        "--pretend")).intersection(self.myopts):
                        return

                if pkg.root != self.target_root:
                        return

                args_set = self._args_set
                if not args_set.findAtomForPackage(pkg):
                        return

                logger = self._logger
                pkg_count = self._pkg_count
                root_config = pkg.root_config
                world_set = root_config.sets["world"]
                world_locked = False
                if hasattr(world_set, "lock"):
                        world_set.lock()
                        world_locked = True

                try:
                        if hasattr(world_set, "load"):
                                world_set.load() # maybe it's changed on disk

                        atom = create_world_atom(pkg, args_set, root_config)
                        if atom:
                                if hasattr(world_set, "add"):
                                        self._status_msg(('Recording %s in "world" ' + \
                                                'favorites file...') % atom)
                                        logger.log(" === (%s of %s) Updating world file (%s)" % \
                                                (pkg_count.curval, pkg_count.maxval, pkg.cpv))
                                        world_set.add(atom)
                                else:
                                        writemsg_level('\n!!! Unable to record %s in "world"\n' % \
                                                (atom,), level=logging.WARN, noiselevel=-1)
                finally:
                        if world_locked:
                                world_set.unlock()

        def _pkg(self, cpv, type_name, root_config, installed=False):
                """
                Get a package instance from the cache, or create a new
                one if necessary. Raises KeyError from aux_get if it
                failures for some reason (package does not exist or is
                corrupt).
                """
                operation = "merge"
                if installed:
                        operation = "nomerge"

                if self._digraph is not None:
                        # Reuse existing instance when available.
                        pkg = self._digraph.get(
                                (type_name, root_config.root, cpv, operation))
                        if pkg is not None:
                                return pkg

                tree_type = depgraph.pkg_tree_map[type_name]
                db = root_config.trees[tree_type].dbapi
                db_keys = list(self.trees[root_config.root][
                        tree_type].dbapi._aux_cache_keys)
                metadata = izip(db_keys, db.aux_get(cpv, db_keys))
                pkg = Package(cpv=cpv, metadata=metadata,
                        root_config=root_config, installed=installed)
                if type_name == "ebuild":
                        settings = self.pkgsettings[root_config.root]
                        settings.setcpv(pkg)
                        pkg.metadata["USE"] = settings["PORTAGE_USE"]

                return pkg

class MetadataRegen(PollScheduler):

        def __init__(self, portdb, max_jobs=None, max_load=None):
                PollScheduler.__init__(self)
                self._portdb = portdb

                if max_jobs is None:
                        max_jobs = 1

                self._max_jobs = max_jobs
                self._max_load = max_load
                self._sched_iface = self._sched_iface_class(
                        register=self._register,
                        schedule=self._schedule_wait,
                        unregister=self._unregister)

                self._valid_pkgs = set()
                self._process_iter = self._iter_metadata_processes()

        def _iter_metadata_processes(self):
                portdb = self._portdb
                valid_pkgs = self._valid_pkgs
                every_cp = portdb.cp_all()
                every_cp.sort(reverse=True)

                while every_cp:
                        cp = every_cp.pop()
                        portage.writemsg_stdout("Processing %s\n" % cp)
                        cpv_list = portdb.cp_list(cp)
                        for cpv in cpv_list:
                                valid_pkgs.add(cpv)
                                ebuild_path, repo_path = portdb.findname2(cpv)
                                metadata_process = portdb._metadata_process(
                                        cpv, ebuild_path, repo_path)
                                if metadata_process is None:
                                        continue
                                yield metadata_process

        def run(self):

                portdb = self._portdb
                from portage.cache.cache_errors import CacheError
                dead_nodes = {}

                for mytree in portdb.porttrees:
                        try:
                                dead_nodes[mytree] = set(portdb.auxdb[mytree].iterkeys())
                        except CacheError, e:
                                portage.writemsg("Error listing cache entries for " + \
                                        "'%s': %s, continuing...\n" % (mytree, e), noiselevel=-1)
                                del e
                                dead_nodes = None
                                break

                while self._schedule():
                        self._poll_loop()

                while self._jobs:
                        self._poll_loop()

                if dead_nodes:
                        for y in self._valid_pkgs:
                                for mytree in portdb.porttrees:
                                        if portdb.findname2(y, mytree=mytree)[0]:
                                                dead_nodes[mytree].discard(y)

                        for mytree, nodes in dead_nodes.iteritems():
                                auxdb = portdb.auxdb[mytree]
                                for y in nodes:
                                        try:
                                                del auxdb[y]
                                        except (KeyError, CacheError):
                                                pass

        def _schedule_tasks(self):
                """
                @rtype: bool
                @returns: True if there may be remaining tasks to schedule,
                        False otherwise.
                """
                while self._can_add_job():
                        try:
                                metadata_process = self._process_iter.next()
                        except StopIteration:
                                return False

                        self._jobs += 1
                        metadata_process.scheduler = self._sched_iface
                        metadata_process.addExitListener(self._metadata_exit)
                        metadata_process.start()
                return True

        def _metadata_exit(self, metadata_process):
                self._jobs -= 1
                if metadata_process.returncode != os.EX_OK:
                        self._valid_pkgs.discard(metadata_process.cpv)
                        portage.writemsg("Error processing %s, continuing...\n" % \
                                (metadata_process.cpv,))
                self._schedule()

class UninstallFailure(portage.exception.PortageException):
        """
        An instance of this class is raised by unmerge() when
        an uninstallation fails.
        """
        status = 1
        def __init__(self, *pargs):
                portage.exception.PortageException.__init__(self, pargs)
                if pargs:
                        self.status = pargs[0]

def unmerge(root_config, myopts, unmerge_action,
        unmerge_files, ldpath_mtimes, autoclean=0,
        clean_world=1, clean_delay=1, ordered=0, raise_on_error=0,
        scheduler=None, writemsg_level=portage.util.writemsg_level):

        quiet = "--quiet" in myopts
        settings = root_config.settings
        sets = root_config.sets
        vartree = root_config.trees["vartree"]
        candidate_catpkgs=[]
        global_unmerge=0
        xterm_titles = "notitles" not in settings.features
        out = portage.output.EOutput()
        pkg_cache = {}
        db_keys = list(vartree.dbapi._aux_cache_keys)

        def _pkg(cpv):
                pkg = pkg_cache.get(cpv)
                if pkg is None:
                        pkg = Package(cpv=cpv, installed=True,
                                metadata=izip(db_keys, vartree.dbapi.aux_get(cpv, db_keys)),
                                root_config=root_config,
                                type_name="installed")
                        pkg_cache[cpv] = pkg
                return pkg

        vdb_path = os.path.join(settings["ROOT"], portage.VDB_PATH)
        try:
                # At least the parent needs to exist for the lock file.
                portage.util.ensure_dirs(vdb_path)
        except portage.exception.PortageException:
                pass
        vdb_lock = None
        try:
                if os.access(vdb_path, os.W_OK):
                        vdb_lock = portage.locks.lockdir(vdb_path)
                realsyslist = sets["system"].getAtoms()
                syslist = []
                for x in realsyslist:
                        mycp = portage.dep_getkey(x)
                        if mycp in settings.getvirtuals():
                                providers = []
                                for provider in settings.getvirtuals()[mycp]:
                                        if vartree.dbapi.match(provider):
                                                providers.append(provider)
                                if len(providers) == 1:
                                        syslist.extend(providers)
                        else:
                                syslist.append(mycp)
        
                mysettings = portage.config(clone=settings)
        
                if not unmerge_files:
                        if unmerge_action == "unmerge":
                                print
                                print bold("emerge unmerge") + " can only be used with specific package names"
                                print
                                return 0
                        else:
                                global_unmerge = 1
        
                localtree = vartree
                # process all arguments and add all
                # valid db entries to candidate_catpkgs
                if global_unmerge:
                        if not unmerge_files:
                                candidate_catpkgs.extend(vartree.dbapi.cp_all())
                else:
                        #we've got command-line arguments
                        if not unmerge_files:
                                print "\nNo packages to unmerge have been provided.\n"
                                return 0
                        for x in unmerge_files:
                                arg_parts = x.split('/')
                                if x[0] not in [".","/"] and \
                                        arg_parts[-1][-7:] != ".ebuild":
                                        #possible cat/pkg or dep; treat as such
                                        candidate_catpkgs.append(x)
                                elif unmerge_action in ["prune","clean"]:
                                        print "\n!!! Prune and clean do not accept individual" + \
                                                " ebuilds as arguments;\n    skipping.\n"
                                        continue
                                else:
                                        # it appears that the user is specifying an installed
                                        # ebuild and we're in "unmerge" mode, so it's ok.
                                        if not os.path.exists(x):
                                                print "\n!!! The path '"+x+"' doesn't exist.\n"
                                                return 0
        
                                        absx   = os.path.abspath(x)
                                        sp_absx = absx.split("/")
                                        if sp_absx[-1][-7:] == ".ebuild":
                                                del sp_absx[-1]
                                                absx = "/".join(sp_absx)
        
                                        sp_absx_len = len(sp_absx)
        
                                        vdb_path = os.path.join(settings["ROOT"], portage.VDB_PATH)
                                        vdb_len  = len(vdb_path)
        
                                        sp_vdb     = vdb_path.split("/")
                                        sp_vdb_len = len(sp_vdb)
        
                                        if not os.path.exists(absx+"/CONTENTS"):
                                                print "!!! Not a valid db dir: "+str(absx)
                                                return 0
        
                                        if sp_absx_len <= sp_vdb_len:
                                                # The Path is shorter... so it can't be inside the vdb.
                                                print sp_absx
                                                print absx
                                                print "\n!!!",x,"cannot be inside "+ \
                                                        vdb_path+"; aborting.\n"
                                                return 0
        
                                        for idx in range(0,sp_vdb_len):
                                                if idx >= sp_absx_len or sp_vdb[idx] != sp_absx[idx]:
                                                        print sp_absx
                                                        print absx
                                                        print "\n!!!", x, "is not inside "+\
                                                                vdb_path+"; aborting.\n"
                                                        return 0
        
                                        print "="+"/".join(sp_absx[sp_vdb_len:])
                                        candidate_catpkgs.append(
                                                "="+"/".join(sp_absx[sp_vdb_len:]))
        
                newline=""
                if (not "--quiet" in myopts):
                        newline="\n"
                if settings["ROOT"] != "/":
                        writemsg_level(darkgreen(newline+ \
                                ">>> Using system located in ROOT tree %s\n" % \
                                settings["ROOT"]))

                if (("--pretend" in myopts) or ("--ask" in myopts)) and \
                        not ("--quiet" in myopts):
                        writemsg_level(darkgreen(newline+\
                                ">>> These are the packages that would be unmerged:\n"))

                # Preservation of order is required for --depclean and --prune so
                # that dependencies are respected. Use all_selected to eliminate
                # duplicate packages since the same package may be selected by
                # multiple atoms.
                pkgmap = []
                all_selected = set()
                for x in candidate_catpkgs:
                        # cycle through all our candidate deps and determine
                        # what will and will not get unmerged
                        try:
                                mymatch = vartree.dbapi.match(x)
                        except portage.exception.AmbiguousPackageName, errpkgs:
                                print "\n\n!!! The short ebuild name \"" + \
                                        x + "\" is ambiguous.  Please specify"
                                print "!!! one of the following fully-qualified " + \
                                        "ebuild names instead:\n"
                                for i in errpkgs[0]:
                                        print "    " + green(i)
                                print
                                sys.exit(1)
        
                        if not mymatch and x[0] not in "<>=~":
                                mymatch = localtree.dep_match(x)
                        if not mymatch:
                                portage.writemsg("\n--- Couldn't find '%s' to %s.\n" % \
                                        (x, unmerge_action), noiselevel=-1)
                                continue

                        pkgmap.append(
                                {"protected": set(), "selected": set(), "omitted": set()})
                        mykey = len(pkgmap) - 1
                        if unmerge_action=="unmerge":
                                        for y in mymatch:
                                                if y not in all_selected:
                                                        pkgmap[mykey]["selected"].add(y)
                                                        all_selected.add(y)
                        elif unmerge_action == "prune":
                                if len(mymatch) == 1:
                                        continue
                                best_version = mymatch[0]
                                best_slot = vartree.getslot(best_version)
                                best_counter = vartree.dbapi.cpv_counter(best_version)
                                for mypkg in mymatch[1:]:
                                        myslot = vartree.getslot(mypkg)
                                        mycounter = vartree.dbapi.cpv_counter(mypkg)
                                        if (myslot == best_slot and mycounter > best_counter) or \
                                                mypkg == portage.best([mypkg, best_version]):
                                                if myslot == best_slot:
                                                        if mycounter < best_counter:
                                                                # On slot collision, keep the one with the
                                                                # highest counter since it is the most
                                                                # recently installed.
                                                                continue
                                                best_version = mypkg
                                                best_slot = myslot
                                                best_counter = mycounter
                                pkgmap[mykey]["protected"].add(best_version)
                                pkgmap[mykey]["selected"].update(mypkg for mypkg in mymatch \
                                        if mypkg != best_version and mypkg not in all_selected)
                                all_selected.update(pkgmap[mykey]["selected"])
                        else:
                                # unmerge_action == "clean"
                                slotmap={}
                                for mypkg in mymatch:
                                        if unmerge_action == "clean":
                                                myslot = localtree.getslot(mypkg)
                                        else:
                                                # since we're pruning, we don't care about slots
                                                # and put all the pkgs in together
                                                myslot = 0
                                        if myslot not in slotmap:
                                                slotmap[myslot] = {}
                                        slotmap[myslot][localtree.dbapi.cpv_counter(mypkg)] = mypkg
                                
                                for myslot in slotmap:
                                        counterkeys = slotmap[myslot].keys()
                                        if not counterkeys:
                                                continue
                                        counterkeys.sort()
                                        pkgmap[mykey]["protected"].add(
                                                slotmap[myslot][counterkeys[-1]])
                                        del counterkeys[-1]
                                        #be pretty and get them in order of merge:
                                        for ckey in counterkeys:
                                                mypkg = slotmap[myslot][ckey]
                                                if mypkg not in all_selected:
                                                        pkgmap[mykey]["selected"].add(mypkg)
                                                        all_selected.add(mypkg)
                                        # ok, now the last-merged package
                                        # is protected, and the rest are selected
                numselected = len(all_selected)
                if global_unmerge and not numselected:
                        portage.writemsg_stdout("\n>>> No outdated packages were found on your system.\n")
                        return 0
        
                if not numselected:
                        portage.writemsg_stdout(
                                "\n>>> No packages selected for removal by " + \
                                unmerge_action + "\n")
                        return 0
        finally:
                if vdb_lock:
                        vartree.dbapi.flush_cache()
                        portage.locks.unlockdir(vdb_lock)
        
        from portage.sets.base import EditablePackageSet
        
        # generate a list of package sets that are directly or indirectly listed in "world",
        # as there is no persistent list of "installed" sets
        installed_sets = ["world"]
        stop = False
        pos = 0
        while not stop:
                stop = True
                pos = len(installed_sets)
                for s in installed_sets[pos - 1:]:
                        if s not in sets:
                                continue
                        candidates = [x[len(SETPREFIX):] for x in sets[s].getNonAtoms() if x.startswith(SETPREFIX)]
                        if candidates:
                                stop = False
                                installed_sets += candidates
        installed_sets = [x for x in installed_sets if x not in root_config.setconfig.active]
        del stop, pos

        # we don't want to unmerge packages that are still listed in user-editable package sets
        # listed in "world" as they would be remerged on the next update of "world" or the 
        # relevant package sets.
        unknown_sets = set()
        for cp in xrange(len(pkgmap)):
                for cpv in pkgmap[cp]["selected"].copy():
                        try:
                                pkg = _pkg(cpv)
                        except KeyError:
                                # It could have been uninstalled
                                # by a concurrent process.
                                continue

                        if unmerge_action != "clean" and \
                                root_config.root == "/" and \
                                portage.match_from_list(
                                portage.const.PORTAGE_PACKAGE_ATOM, [pkg]):
                                msg = ("Not unmerging package %s since there is no valid " + \
                                "reason for portage to unmerge itself.") % (pkg.cpv,)
                                for line in textwrap.wrap(msg, 75):
                                        out.eerror(line)
                                # adjust pkgmap so the display output is correct
                                pkgmap[cp]["selected"].remove(cpv)
                                all_selected.remove(cpv)
                                pkgmap[cp]["protected"].add(cpv)
                                continue

                        parents = []
                        for s in installed_sets:
                                # skip sets that the user requested to unmerge, and skip world 
                                # unless we're unmerging a package set (as the package would be 
                                # removed from "world" later on)
                                if s in root_config.setconfig.active or (s == "world" and not root_config.setconfig.active):
                                        continue

                                if s not in sets:
                                        if s in unknown_sets:
                                                continue
                                        unknown_sets.add(s)
                                        out = portage.output.EOutput()
                                        out.eerror(("Unknown set '@%s' in " + \
                                                "%svar/lib/portage/world_sets") % \
                                                (s, root_config.root))
                                        continue

                                # only check instances of EditablePackageSet as other classes are generally used for
                                # special purposes and can be ignored here (and are usually generated dynamically, so the
                                # user can't do much about them anyway)
                                if isinstance(sets[s], EditablePackageSet):

                                        # This is derived from a snippet of code in the
                                        # depgraph._iter_atoms_for_pkg() method.
                                        for atom in sets[s].iterAtomsForPackage(pkg):
                                                inst_matches = vartree.dbapi.match(atom)
                                                inst_matches.reverse() # descending order
                                                higher_slot = None
                                                for inst_cpv in inst_matches:
                                                        try:
                                                                inst_pkg = _pkg(inst_cpv)
                                                        except KeyError:
                                                                # It could have been uninstalled
                                                                # by a concurrent process.
                                                                continue

                                                        if inst_pkg.cp != atom.cp:
                                                                continue
                                                        if pkg >= inst_pkg:
                                                                # This is descending order, and we're not
                                                                # interested in any versions <= pkg given.
                                                                break
                                                        if pkg.slot_atom != inst_pkg.slot_atom:
                                                                higher_slot = inst_pkg
                                                                break
                                                if higher_slot is None:
                                                        parents.append(s)
                                                        break
                        if parents:
                                #print colorize("WARN", "Package %s is going to be unmerged," % cpv)
                                #print colorize("WARN", "but still listed in the following package sets:")
                                #print "    %s\n" % ", ".join(parents)
                                print colorize("WARN", "Not unmerging package %s as it is" % cpv)
                                print colorize("WARN", "still referenced by the following package sets:")
                                print "    %s\n" % ", ".join(parents)
                                # adjust pkgmap so the display output is correct
                                pkgmap[cp]["selected"].remove(cpv)
                                all_selected.remove(cpv)
                                pkgmap[cp]["protected"].add(cpv)
        
        del installed_sets

        numselected = len(all_selected)
        if not numselected:
                writemsg_level(
                        "\n>>> No packages selected for removal by " + \
                        unmerge_action + "\n")
                return 0

        # Unmerge order only matters in some cases
        if not ordered:
                unordered = {}
                for d in pkgmap:
                        selected = d["selected"]
                        if not selected:
                                continue
                        cp = portage.cpv_getkey(iter(selected).next())
                        cp_dict = unordered.get(cp)
                        if cp_dict is None:
                                cp_dict = {}
                                unordered[cp] = cp_dict
                                for k in d:
                                        cp_dict[k] = set()
                        for k, v in d.iteritems():
                                cp_dict[k].update(v)
                pkgmap = [unordered[cp] for cp in sorted(unordered)]

        for x in xrange(len(pkgmap)):
                selected = pkgmap[x]["selected"]
                if not selected:
                        continue
                for mytype, mylist in pkgmap[x].iteritems():
                        if mytype == "selected":
                                continue
                        mylist.difference_update(all_selected)
                cp = portage.cpv_getkey(iter(selected).next())
                for y in localtree.dep_match(cp):
                        if y not in pkgmap[x]["omitted"] and \
                                y not in pkgmap[x]["selected"] and \
                                y not in pkgmap[x]["protected"] and \
                                y not in all_selected:
                                pkgmap[x]["omitted"].add(y)
                if global_unmerge and not pkgmap[x]["selected"]:
                        #avoid cluttering the preview printout with stuff that isn't getting unmerged
                        continue
                if not (pkgmap[x]["protected"] or pkgmap[x]["omitted"]) and cp in syslist:
                        writemsg_level(colorize("BAD","\a\n\n!!! " + \
                                "'%s' is part of your system profile.\n" % cp),
                                level=logging.WARNING, noiselevel=-1)
                        writemsg_level(colorize("WARN","\a!!! Unmerging it may " + \
                                "be damaging to your system.\n\n"),
                                level=logging.WARNING, noiselevel=-1)
                        if clean_delay and "--pretend" not in myopts and "--ask" not in myopts:
                                countdown(int(settings["EMERGE_WARNING_DELAY"]),
                                        colorize("UNMERGE_WARN", "Press Ctrl-C to Stop"))
                if not quiet:
                        writemsg_level("\n %s\n" % (bold(cp),), noiselevel=-1)
                else:
                        writemsg_level(bold(cp) + ": ", noiselevel=-1)
                for mytype in ["selected","protected","omitted"]:
                        if not quiet:
                                writemsg_level((mytype + ": ").rjust(14), noiselevel=-1)
                        if pkgmap[x][mytype]:
                                sorted_pkgs = [portage.catpkgsplit(mypkg)[1:] for mypkg in pkgmap[x][mytype]]
                                sorted_pkgs.sort(portage.pkgcmp)
                                for pn, ver, rev in sorted_pkgs:
                                        if rev == "r0":
                                                myversion = ver
                                        else:
                                                myversion = ver + "-" + rev
                                        if mytype == "selected":
                                                writemsg_level(
                                                        colorize("UNMERGE_WARN", myversion + " "),
                                                        noiselevel=-1)
                                        else:
                                                writemsg_level(
                                                        colorize("GOOD", myversion + " "), noiselevel=-1)
                        else:
                                writemsg_level("none ", noiselevel=-1)
                        if not quiet:
                                writemsg_level("\n", noiselevel=-1)
                if quiet:
                        writemsg_level("\n", noiselevel=-1)

        writemsg_level("\n>>> " + colorize("UNMERGE_WARN", "'Selected'") + \
                " packages are slated for removal.\n")
        writemsg_level(">>> " + colorize("GOOD", "'Protected'") + \
                        " and " + colorize("GOOD", "'omitted'") + \
                        " packages will not be removed.\n\n")

        if "--pretend" in myopts:
                #we're done... return
                return 0
        if "--ask" in myopts:
                if userquery("Would you like to unmerge these packages?")=="No":
                        # enter pretend mode for correct formatting of results
                        myopts["--pretend"] = True
                        print
                        print "Quitting."
                        print
                        return 0
        #the real unmerging begins, after a short delay....
        if clean_delay and not autoclean:
                countdown(int(settings["CLEAN_DELAY"]), ">>> Unmerging")

        for x in xrange(len(pkgmap)):
                for y in pkgmap[x]["selected"]:
                        writemsg_level(">>> Unmerging "+y+"...\n", noiselevel=-1)
                        emergelog(xterm_titles, "=== Unmerging... ("+y+")")
                        mysplit = y.split("/")
                        #unmerge...
                        retval = portage.unmerge(mysplit[0], mysplit[1], settings["ROOT"],
                                mysettings, unmerge_action not in ["clean","prune"],
                                vartree=vartree, ldpath_mtimes=ldpath_mtimes,
                                scheduler=scheduler)

                        if retval != os.EX_OK:
                                emergelog(xterm_titles, " !!! unmerge FAILURE: "+y)
                                if raise_on_error:
                                        raise UninstallFailure(retval)
                                sys.exit(retval)
                        else:
                                if clean_world and hasattr(sets["world"], "cleanPackage"):
                                        sets["world"].cleanPackage(vartree.dbapi, y)
                                emergelog(xterm_titles, " >>> unmerge success: "+y)
        if clean_world and hasattr(sets["world"], "remove"):
                for s in root_config.setconfig.active:
                        sets["world"].remove(SETPREFIX+s)
        return 1

def chk_updated_info_files(root, infodirs, prev_mtimes, retval):

        if os.path.exists("/usr/bin/install-info"):
                out = portage.output.EOutput()
                regen_infodirs=[]
                for z in infodirs:
                        if z=='':
                                continue
                        inforoot=normpath(root+z)
                        if os.path.isdir(inforoot):
                                infomtime = long(os.stat(inforoot).st_mtime)
                                if inforoot not in prev_mtimes or \
                                        prev_mtimes[inforoot] != infomtime:
                                                regen_infodirs.append(inforoot)

                if not regen_infodirs:
                        portage.writemsg_stdout("\n")
                        out.einfo("GNU info directory index is up-to-date.")
                else:
                        portage.writemsg_stdout("\n")
                        out.einfo("Regenerating GNU info directory index...")

                        dir_extensions = ("", ".gz", ".bz2")
                        icount=0
                        badcount=0
                        errmsg = ""
                        for inforoot in regen_infodirs:
                                if inforoot=='':
                                        continue

                                if not os.path.isdir(inforoot) or \
                                        not os.access(inforoot, os.W_OK):
                                        continue

                                file_list = os.listdir(inforoot)
                                file_list.sort()
                                dir_file = os.path.join(inforoot, "dir")
                                moved_old_dir = False
                                processed_count = 0
                                for x in file_list:
                                        if x.startswith(".") or \
                                                os.path.isdir(os.path.join(inforoot, x)):
                                                continue
                                        if x.startswith("dir"):
                                                skip = False
                                                for ext in dir_extensions:
                                                        if x == "dir" + ext or \
                                                                x == "dir" + ext + ".old":
                                                                skip = True
                                                                break
                                                if skip:
                                                        continue
                                        if processed_count == 0:
                                                for ext in dir_extensions:
                                                        try:
                                                                os.rename(dir_file + ext, dir_file + ext + ".old")
                                                                moved_old_dir = True
                                                        except EnvironmentError, e:
                                                                if e.errno != errno.ENOENT:
                                                                        raise
                                                                del e
                                        processed_count += 1
                                        myso=commands.getstatusoutput("LANG=C LANGUAGE=C /usr/bin/install-info --dir-file="+inforoot+"/dir "+inforoot+"/"+x)[1]
                                        existsstr="already exists, for file `"
                                        if myso!="":
                                                if re.search(existsstr,myso):
                                                        # Already exists... Don't increment the count for this.
                                                        pass
                                                elif myso[:44]=="install-info: warning: no info dir entry in ":
                                                        # This info file doesn't contain a DIR-header: install-info produces this
                                                        # (harmless) warning (the --quiet switch doesn't seem to work).
                                                        # Don't increment the count for this.
                                                        pass
                                                else:
                                                        badcount=badcount+1
                                                        errmsg += myso + "\n"
                                        icount=icount+1

                                if moved_old_dir and not os.path.exists(dir_file):
                                        # We didn't generate a new dir file, so put the old file
                                        # back where it was originally found.
                                        for ext in dir_extensions:
                                                try:
                                                        os.rename(dir_file + ext + ".old", dir_file + ext)
                                                except EnvironmentError, e:
                                                        if e.errno != errno.ENOENT:
                                                                raise
                                                        del e

                                # Clean dir.old cruft so that they don't prevent
                                # unmerge of otherwise empty directories.
                                for ext in dir_extensions:
                                        try:
                                                os.unlink(dir_file + ext + ".old")
                                        except EnvironmentError, e:
                                                if e.errno != errno.ENOENT:
                                                        raise
                                                del e

                                #update mtime so we can potentially avoid regenerating.
                                prev_mtimes[inforoot] = long(os.stat(inforoot).st_mtime)

                        if badcount:
                                out.eerror("Processed %d info files; %d errors." % \
                                        (icount, badcount))
                                writemsg_level(errmsg, level=logging.ERROR, noiselevel=-1)
                        else:
                                if icount > 0:
                                        out.einfo("Processed %d info files." % (icount,))


def display_news_notification(root_config, myopts):
        target_root = root_config.root
        trees = root_config.trees
        settings = trees["vartree"].settings
        portdb = trees["porttree"].dbapi
        vardb = trees["vartree"].dbapi
        NEWS_PATH = os.path.join("metadata", "news")
        UNREAD_PATH = os.path.join(target_root, NEWS_LIB_PATH, "news")
        newsReaderDisplay = False
        update = "--pretend" not in myopts

        for repo in portdb.getRepositories():
                unreadItems = checkUpdatedNewsItems(
                        portdb, vardb, NEWS_PATH, UNREAD_PATH, repo, update=update)
                if unreadItems:
                        if not newsReaderDisplay:
                                newsReaderDisplay = True
                                print
                        print colorize("WARN", " * IMPORTANT:"),
                        print "%s news items need reading for repository '%s'." % (unreadItems, repo)
                        
        
        if newsReaderDisplay:
                print colorize("WARN", " *"),
                print "Use " + colorize("GOOD", "eselect news") + " to read news items."
                print

def display_preserved_libs(vardbapi):
        MAX_DISPLAY = 3

        # Ensure the registry is consistent with existing files.
        vardbapi.plib_registry.pruneNonExisting()

        if vardbapi.plib_registry.hasEntries():
                print
                print colorize("WARN", "!!!") + " existing preserved libs:"
                plibdata = vardbapi.plib_registry.getPreservedLibs()
                linkmap = vardbapi.linkmap
                consumer_map = {}
                owners = {}
                linkmap_broken = False

                try:
                        linkmap.rebuild()
                except portage.exception.CommandNotFound, e:
                        writemsg_level("!!! Command Not Found: %s\n" % (e,),
                                level=logging.ERROR, noiselevel=-1)
                        del e
                        linkmap_broken = True
                else:
                        search_for_owners = set()
                        for cpv in plibdata:
                                for f in plibdata[cpv]:
                                        if f in consumer_map:
                                                continue
                                        consumers = list(linkmap.findConsumers(f))
                                        consumers.sort()
                                        consumer_map[f] = consumers
                                        search_for_owners.update(consumers[:MAX_DISPLAY+1])

                        owners = vardbapi._owners.getFileOwnerMap(search_for_owners)

                for cpv in plibdata:
                        print colorize("WARN", ">>>") + " package: %s" % cpv
                        samefile_map = {}
                        for f in plibdata[cpv]:
                                obj_key = linkmap._obj_key(f)
                                alt_paths = samefile_map.get(obj_key)
                                if alt_paths is None:
                                        alt_paths = set()
                                        samefile_map[obj_key] = alt_paths
                                alt_paths.add(f)

                        for alt_paths in samefile_map.itervalues():
                                alt_paths = sorted(alt_paths)
                                for p in alt_paths:
                                        print colorize("WARN", " * ") + " - %s" % (p,)
                                f = alt_paths[0]
                                consumers = consumer_map.get(f, [])
                                for c in consumers[:MAX_DISPLAY]:
                                        print colorize("WARN", " * ") + "     used by %s (%s)" % \
                                                (c, ", ".join(x.mycpv for x in owners.get(c, [])))
                                if len(consumers) == MAX_DISPLAY + 1:
                                        print colorize("WARN", " * ") + "     used by %s (%s)" % \
                                                (consumers[MAX_DISPLAY], ", ".join(x.mycpv \
                                                for x in owners.get(consumers[MAX_DISPLAY], [])))
                                elif len(consumers) > MAX_DISPLAY:
                                        print colorize("WARN", " * ") + "     used by %d other files" % (len(consumers) - MAX_DISPLAY)
                print "Use " + colorize("GOOD", "emerge @preserved-rebuild") + " to rebuild packages using these libraries"


def _flush_elog_mod_echo():
        """
        Dump the mod_echo output now so that our other
        notifications are shown last.
        @rtype: bool
        @returns: True if messages were shown, False otherwise.
        """
        messages_shown = False
        try:
                from portage.elog import mod_echo
        except ImportError:
                pass # happens during downgrade to a version without the module
        else:
                messages_shown = bool(mod_echo._items)
                mod_echo.finalize()
        return messages_shown

def post_emerge(root_config, myopts, mtimedb, retval):
        """
        Misc. things to run at the end of a merge session.
        
        Update Info Files
        Update Config Files
        Update News Items
        Commit mtimeDB
        Display preserved libs warnings
        Exit Emerge

        @param trees: A dictionary mapping each ROOT to it's package databases
        @type trees: dict
        @param mtimedb: The mtimeDB to store data needed across merge invocations
        @type mtimedb: MtimeDB class instance
        @param retval: Emerge's return value
        @type retval: Int
        @rype: None
        @returns:
        1.  Calls sys.exit(retval)
        """

        target_root = root_config.root
        trees = { target_root : root_config.trees }
        vardbapi = trees[target_root]["vartree"].dbapi
        settings = vardbapi.settings
        info_mtimes = mtimedb["info"]

        # Load the most current variables from ${ROOT}/etc/profile.env
        settings.unlock()
        settings.reload()
        settings.regenerate()
        settings.lock()

        config_protect = settings.get("CONFIG_PROTECT","").split()
        infodirs = settings.get("INFOPATH","").split(":") + \
                settings.get("INFODIR","").split(":")

        os.chdir("/")

        if retval == os.EX_OK:
                exit_msg = " *** exiting successfully."
        else:
                exit_msg = " *** exiting unsuccessfully with status '%s'." % retval
        emergelog("notitles" not in settings.features, exit_msg)

        _flush_elog_mod_echo()

        counter_hash = settings.get("PORTAGE_COUNTER_HASH")
        if counter_hash is not None and \
                counter_hash == vardbapi._counter_hash():
                # If vdb state has not changed then there's nothing else to do.
                sys.exit(retval)

        vdb_path = os.path.join(target_root, portage.VDB_PATH)
        portage.util.ensure_dirs(vdb_path)
        vdb_lock = None
        if os.access(vdb_path, os.W_OK) and not "--pretend" in myopts:
                vdb_lock = portage.locks.lockdir(vdb_path)

        if vdb_lock:
                try:
                        if "noinfo" not in settings.features:
                                chk_updated_info_files(target_root,
                                        infodirs, info_mtimes, retval)
                        mtimedb.commit()
                finally:
                        if vdb_lock:
                                portage.locks.unlockdir(vdb_lock)

        chk_updated_cfg_files(target_root, config_protect)
        
        display_news_notification(root_config, myopts)
        if retval in (None, os.EX_OK) or (not "--pretend" in myopts):
                display_preserved_libs(vardbapi)        

        sys.exit(retval)


def chk_updated_cfg_files(target_root, config_protect):
        if config_protect:
                #number of directories with some protect files in them
                procount=0
                for x in config_protect:
                        x = os.path.join(target_root, x.lstrip(os.path.sep))
                        if not os.access(x, os.W_OK):
                                # Avoid Permission denied errors generated
                                # later by `find`.
                                continue
                        try:
                                mymode = os.lstat(x).st_mode
                        except OSError:
                                continue
                        if stat.S_ISLNK(mymode):
                                # We want to treat it like a directory if it
                                # is a symlink to an existing directory.
                                try:
                                        real_mode = os.stat(x).st_mode
                                        if stat.S_ISDIR(real_mode):
                                                mymode = real_mode
                                except OSError:
                                        pass
                        if stat.S_ISDIR(mymode):
                                mycommand = "find '%s' -name '.*' -type d -prune -o -name '._cfg????_*'" % x
                        else:
                                mycommand = "find '%s' -maxdepth 1 -name '._cfg????_%s'" % \
                                        os.path.split(x.rstrip(os.path.sep))
                        mycommand += " ! -name '.*~' ! -iname '.*.bak' -print0"
                        a = commands.getstatusoutput(mycommand)
                        if a[0] != 0:
                                sys.stderr.write(" %s error scanning '%s': " % (bad("*"), x))
                                sys.stderr.flush()
                                # Show the error message alone, sending stdout to /dev/null.
                                os.system(mycommand + " 1>/dev/null")
                        else:
                                files = a[1].split('\0')
                                # split always produces an empty string as the last element
                                if files and not files[-1]:
                                        del files[-1]
                                if files:
                                        procount += 1
                                        print "\n"+colorize("WARN", " * IMPORTANT:"),
                                        if stat.S_ISDIR(mymode):
                                                 print "%d config files in '%s' need updating." % \
                                                        (len(files), x)
                                        else:
                                                 print "config file '%s' needs updating." % x

                if procount:
                        print " "+yellow("*")+" See the "+colorize("INFORM","CONFIGURATION FILES")+ \
                                " section of the " + bold("emerge")
                        print " "+yellow("*")+" man page to learn how to update config files."

def checkUpdatedNewsItems(portdb, vardb, NEWS_PATH, UNREAD_PATH, repo_id,
        update=False):
        """
        Examines news items in repodir + '/' + NEWS_PATH and attempts to find unread items
        Returns the number of unread (yet relevent) items.
        
        @param portdb: a portage tree database
        @type portdb: pordbapi
        @param vardb: an installed package database
        @type vardb: vardbapi
        @param NEWS_PATH:
        @type NEWS_PATH:
        @param UNREAD_PATH:
        @type UNREAD_PATH:
        @param repo_id:
        @type repo_id:
        @rtype: Integer
        @returns:
        1.  The number of unread but relevant news items.
        
        """
        from portage.news import NewsManager
        manager = NewsManager(portdb, vardb, NEWS_PATH, UNREAD_PATH)
        return manager.getUnreadItems( repo_id, update=update )

def insert_category_into_atom(atom, category):
        alphanum = re.search(r'\w', atom)
        if alphanum:
                ret = atom[:alphanum.start()] + "%s/" % category + \
                        atom[alphanum.start():]
        else:
                ret = None
        return ret

def is_valid_package_atom(x):
        if "/" not in x:
                alphanum = re.search(r'\w', x)
                if alphanum:
                        x = x[:alphanum.start()] + "cat/" + x[alphanum.start():]
        return portage.isvalidatom(x)

def show_blocker_docs_link():
        print
        print "For more information about " + bad("Blocked Packages") + ", please refer to the following"
        print "section of the Gentoo Linux x86 Handbook (architecture is irrelevant):"
        print
        print "http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked"
        print

def show_mask_docs():
        print "For more information, see the MASKED PACKAGES section in the emerge"
        print "man page or refer to the Gentoo Handbook."

def action_sync(settings, trees, mtimedb, myopts, myaction):
        xterm_titles = "notitles" not in settings.features
        emergelog(xterm_titles, " === sync")
        myportdir = settings.get("PORTDIR", None)
        out = portage.output.EOutput()
        if not myportdir:
                sys.stderr.write("!!! PORTDIR is undefined.  Is /etc/make.globals missing?\n")
                sys.exit(1)
        if myportdir[-1]=="/":
                myportdir=myportdir[:-1]
        if not os.path.exists(myportdir):
                print ">>>",myportdir,"not found, creating it."
                os.makedirs(myportdir,0755)
        syncuri = settings.get("SYNC", "").strip()
        if not syncuri:
                writemsg_level("!!! SYNC is undefined. Is /etc/make.globals missing?\n",
                        noiselevel=-1, level=logging.ERROR)
                return 1

        os.umask(0022)
        updatecache_flg = False
        if myaction == "metadata":
                print "skipping sync"
                updatecache_flg = True
        elif syncuri[:8]=="rsync://":
                if not os.path.exists("/usr/bin/rsync"):
                        print "!!! /usr/bin/rsync does not exist, so rsync support is disabled."
                        print "!!! Type \"emerge net-misc/rsync\" to enable rsync support."
                        sys.exit(1)
                mytimeout=180

                rsync_opts = []
                import shlex, StringIO
                if settings["PORTAGE_RSYNC_OPTS"] == "":
                        portage.writemsg("PORTAGE_RSYNC_OPTS empty or unset, using hardcoded defaults\n")
                        rsync_opts.extend([
                                "--recursive",    # Recurse directories
                                "--links",        # Consider symlinks
                                "--safe-links",   # Ignore links outside of tree
                                "--perms",        # Preserve permissions
                                "--times",        # Preserive mod times
                                "--compress",     # Compress the data transmitted
                                "--force",        # Force deletion on non-empty dirs
                                "--whole-file",   # Don't do block transfers, only entire files
                                "--delete",       # Delete files that aren't in the master tree
                                "--stats",        # Show final statistics about what was transfered
                                "--timeout="+str(mytimeout), # IO timeout if not done in X seconds
                                "--exclude=/distfiles",   # Exclude distfiles from consideration
                                "--exclude=/local",       # Exclude local     from consideration
                                "--exclude=/packages",    # Exclude packages  from consideration
                        ])

                else:
                        # The below validation is not needed when using the above hardcoded
                        # defaults.

                        portage.writemsg("Using PORTAGE_RSYNC_OPTS instead of hardcoded defaults\n", 1)
                        lexer = shlex.shlex(StringIO.StringIO(
                                settings.get("PORTAGE_RSYNC_OPTS","")), posix=True)
                        lexer.whitespace_split = True
                        rsync_opts.extend(lexer)
                        del lexer

                        for opt in ("--recursive", "--times"):
                                if opt not in rsync_opts:
                                        portage.writemsg(yellow("WARNING:") + " adding required option " + \
                                        "%s not included in PORTAGE_RSYNC_OPTS\n" % opt)
                                        rsync_opts.append(opt)
        
                        for exclude in ("distfiles", "local", "packages"):
                                opt = "--exclude=/%s" % exclude
                                if opt not in rsync_opts:
                                        portage.writemsg(yellow("WARNING:") + \
                                        " adding required option %s not included in "  % opt + \
                                        "PORTAGE_RSYNC_OPTS (can be overridden with --exclude='!')\n")
                                        rsync_opts.append(opt)
        
                        if syncuri.rstrip("/").endswith(".gentoo.org/gentoo-portage"):
                                def rsync_opt_startswith(opt_prefix):
                                        for x in rsync_opts:
                                                if x.startswith(opt_prefix):
                                                        return True
                                        return False

                                if not rsync_opt_startswith("--timeout="):
                                        rsync_opts.append("--timeout=%d" % mytimeout)

                                for opt in ("--compress", "--whole-file"):
                                        if opt not in rsync_opts:
                                                portage.writemsg(yellow("WARNING:") + " adding required option " + \
                                                "%s not included in PORTAGE_RSYNC_OPTS\n" % opt)
                                                rsync_opts.append(opt)

                if "--quiet" in myopts:
                        rsync_opts.append("--quiet")    # Shut up a lot
                else:
                        rsync_opts.append("--verbose")  # Print filelist

                if "--verbose" in myopts:
                        rsync_opts.append("--progress")  # Progress meter for each file

                if "--debug" in myopts:
                        rsync_opts.append("--checksum") # Force checksum on all files

                # Real local timestamp file.
                servertimestampfile = os.path.join(
                        myportdir, "metadata", "timestamp.chk")

                content = portage.util.grabfile(servertimestampfile)
                mytimestamp = 0
                if content:
                        try:
                                mytimestamp = time.mktime(time.strptime(content[0],
                                        "%a, %d %b %Y %H:%M:%S +0000"))
                        except (OverflowError, ValueError):
                                pass
                del content

                try:
                        rsync_initial_timeout = \
                                int(settings.get("PORTAGE_RSYNC_INITIAL_TIMEOUT", "15"))
                except ValueError:
                        rsync_initial_timeout = 15

                try:
                        maxretries=int(settings["PORTAGE_RSYNC_RETRIES"])
                except SystemExit, e:
                        raise # Needed else can't exit
                except:
                        maxretries=3 #default number of retries

                retries=0
                user_name, hostname, port = re.split(
                        "rsync://([^:/]+@)?([^:/]*)(:[0-9]+)?", syncuri, maxsplit=3)[1:4]
                if port is None:
                        port=""
                if user_name is None:
                        user_name=""
                updatecache_flg=True
                all_rsync_opts = set(rsync_opts)
                lexer = shlex.shlex(StringIO.StringIO(
                        settings.get("PORTAGE_RSYNC_EXTRA_OPTS","")), posix=True)
                lexer.whitespace_split = True
                extra_rsync_opts = list(lexer)
                del lexer
                all_rsync_opts.update(extra_rsync_opts)
                family = socket.AF_INET
                if "-4" in all_rsync_opts or "--ipv4" in all_rsync_opts:
                        family = socket.AF_INET
                elif socket.has_ipv6 and \
                        ("-6" in all_rsync_opts or "--ipv6" in all_rsync_opts):
                        family = socket.AF_INET6
                ips=[]
                SERVER_OUT_OF_DATE = -1
                EXCEEDED_MAX_RETRIES = -2
                while (1):
                        if ips:
                                del ips[0]
                        if ips==[]:
                                try:
                                        for addrinfo in socket.getaddrinfo(
                                                hostname, None, family, socket.SOCK_STREAM):
                                                if socket.has_ipv6 and addrinfo[0] == socket.AF_INET6:
                                                        # IPv6 addresses need to be enclosed in square brackets
                                                        ips.append("[%s]" % addrinfo[4][0])
                                                else:
                                                        ips.append(addrinfo[4][0])
                                        from random import shuffle
                                        shuffle(ips)
                                except SystemExit, e:
                                        raise # Needed else can't exit
                                except Exception, e:
                                        print "Notice:",str(e)
                                        dosyncuri=syncuri

                        if ips:
                                try:
                                        dosyncuri = syncuri.replace(
                                                "//" + user_name + hostname + port + "/",
                                                "//" + user_name + ips[0] + port + "/", 1)
                                except SystemExit, e:
                                        raise # Needed else can't exit
                                except Exception, e:
                                        print "Notice:",str(e)
                                        dosyncuri=syncuri

                        if (retries==0):
                                if "--ask" in myopts:
                                        if userquery("Do you want to sync your Portage tree with the mirror at\n" + blue(dosyncuri) + bold("?"))=="No":
                                                print
                                                print "Quitting."
                                                print
                                                sys.exit(0)
                                emergelog(xterm_titles, ">>> Starting rsync with " + dosyncuri)
                                if "--quiet" not in myopts:
                                        print ">>> Starting rsync with "+dosyncuri+"..."
                        else:
                                emergelog(xterm_titles,
                                        ">>> Starting retry %d of %d with %s" % \
                                                (retries,maxretries,dosyncuri))
                                print "\n\n>>> Starting retry %d of %d with %s" % (retries,maxretries,dosyncuri)

                        if mytimestamp != 0 and "--quiet" not in myopts:
                                print ">>> Checking server timestamp ..."

                        rsynccommand = ["/usr/bin/rsync"] + rsync_opts + extra_rsync_opts

                        if "--debug" in myopts:
                                print rsynccommand

                        exitcode = os.EX_OK
                        servertimestamp = 0
                        # Even if there's no timestamp available locally, fetch the
                        # timestamp anyway as an initial probe to verify that the server is
                        # responsive.  This protects us from hanging indefinitely on a
                        # connection attempt to an unresponsive server which rsync's
                        # --timeout option does not prevent.
                        if True:
                                # Temporary file for remote server timestamp comparison.
                                from tempfile import mkstemp
                                fd, tmpservertimestampfile = mkstemp()
                                os.close(fd)
                                mycommand = rsynccommand[:]
                                mycommand.append(dosyncuri.rstrip("/") + \
                                        "/metadata/timestamp.chk")
                                mycommand.append(tmpservertimestampfile)
                                content = None
                                mypids = []
                                try:
                                        def timeout_handler(signum, frame):
                                                raise portage.exception.PortageException("timed out")
                                        signal.signal(signal.SIGALRM, timeout_handler)
                                        # Timeout here in case the server is unresponsive.  The
                                        # --timeout rsync option doesn't apply to the initial
                                        # connection attempt.
                                        if rsync_initial_timeout:
                                                signal.alarm(rsync_initial_timeout)
                                        try:
                                                mypids.extend(portage.process.spawn(
                                                        mycommand, env=settings.environ(), returnpid=True))
                                                exitcode = os.waitpid(mypids[0], 0)[1]
                                                content = portage.grabfile(tmpservertimestampfile)
                                        finally:
                                                if rsync_initial_timeout:
                                                        signal.alarm(0)
                                                try:
                                                        os.unlink(tmpservertimestampfile)
                                                except OSError:
                                                        pass
                                except portage.exception.PortageException, e:
                                        # timed out
                                        print e
                                        del e
                                        if mypids and os.waitpid(mypids[0], os.WNOHANG) == (0,0):
                                                os.kill(mypids[0], signal.SIGTERM)
                                                os.waitpid(mypids[0], 0)
                                        # This is the same code rsync uses for timeout.
                                        exitcode = 30
                                else:
                                        if exitcode != os.EX_OK:
                                                if exitcode & 0xff:
                                                        exitcode = (exitcode & 0xff) << 8
                                                else:
                                                        exitcode = exitcode >> 8
                                if mypids:
                                        portage.process.spawned_pids.remove(mypids[0])
                                if content:
                                        try:
                                                servertimestamp = time.mktime(time.strptime(
                                                        content[0], "%a, %d %b %Y %H:%M:%S +0000"))
                                        except (OverflowError, ValueError):
                                                pass
                                del mycommand, mypids, content
                        if exitcode == os.EX_OK:
                                if (servertimestamp != 0) and (servertimestamp == mytimestamp):
                                        emergelog(xterm_titles,
                                                ">>> Cancelling sync -- Already current.")
                                        print
                                        print ">>>"
                                        print ">>> Timestamps on the server and in the local repository are the same."
                                        print ">>> Cancelling all further sync action. You are already up to date."
                                        print ">>>"
                                        print ">>> In order to force sync, remove '%s'." % servertimestampfile
                                        print ">>>"
                                        print
                                        sys.exit(0)
                                elif (servertimestamp != 0) and (servertimestamp < mytimestamp):
                                        emergelog(xterm_titles,
                                                ">>> Server out of date: %s" % dosyncuri)
                                        print
                                        print ">>>"
                                        print ">>> SERVER OUT OF DATE: %s" % dosyncuri
                                        print ">>>"
                                        print ">>> In order to force sync, remove '%s'." % servertimestampfile
                                        print ">>>"
                                        print
                                        exitcode = SERVER_OUT_OF_DATE
                                elif (servertimestamp == 0) or (servertimestamp > mytimestamp):
                                        # actual sync
                                        mycommand = rsynccommand + [dosyncuri+"/", myportdir]
                                        exitcode = portage.process.spawn(mycommand,
                                                env=settings.environ())
                                        if exitcode in [0,1,3,4,11,14,20,21]:
                                                break
                        elif exitcode in [1,3,4,11,14,20,21]:
                                break
                        else:
                                # Code 2 indicates protocol incompatibility, which is expected
                                # for servers with protocol < 29 that don't support
                                # --prune-empty-directories.  Retry for a server that supports
                                # at least rsync protocol version 29 (>=rsync-2.6.4).
                                pass

                        retries=retries+1

                        if retries<=maxretries:
                                print ">>> Retrying..."
                                time.sleep(11)
                        else:
                                # over retries
                                # exit loop
                                updatecache_flg=False
                                exitcode = EXCEEDED_MAX_RETRIES
                                break

                if (exitcode==0):
                        emergelog(xterm_titles, "=== Sync completed with %s" % dosyncuri)
                elif exitcode == SERVER_OUT_OF_DATE:
                        sys.exit(1)
                elif exitcode == EXCEEDED_MAX_RETRIES:
                        sys.stderr.write(
                                ">>> Exceeded PORTAGE_RSYNC_RETRIES: %s\n" % maxretries)
                        sys.exit(1)
                elif (exitcode>0):
                        msg = []
                        if exitcode==1:
                                msg.append("Rsync has reported that there is a syntax error. Please ensure")
                                msg.append("that your SYNC statement is proper.")
                                msg.append("SYNC=" + settings["SYNC"])
                        elif exitcode==11:
                                msg.append("Rsync has reported that there is a File IO error. Normally")
                                msg.append("this means your disk is full, but can be caused by corruption")
                                msg.append("on the filesystem that contains PORTDIR. Please investigate")
                                msg.append("and try again after the problem has been fixed.")
                                msg.append("PORTDIR=" + settings["PORTDIR"])
                        elif exitcode==20:
                                msg.append("Rsync was killed before it finished.")
                        else:
                                msg.append("Rsync has not successfully finished. It is recommended that you keep")
                                msg.append("trying or that you use the 'emerge-webrsync' option if you are unable")
                                msg.append("to use rsync due to firewall or other restrictions. This should be a")
                                msg.append("temporary problem unless complications exist with your network")
                                msg.append("(and possibly your system's filesystem) configuration.")
                        for line in msg:
                                out.eerror(line)
                        sys.exit(exitcode)
        elif syncuri[:6]=="cvs://":
                if not os.path.exists("/usr/bin/cvs"):
                        print "!!! /usr/bin/cvs does not exist, so CVS support is disabled."
                        print "!!! Type \"emerge dev-util/cvs\" to enable CVS support."
                        sys.exit(1)
                cvsroot=syncuri[6:]
                cvsdir=os.path.dirname(myportdir)
                if not os.path.exists(myportdir+"/CVS"):
                        #initial checkout
                        print ">>> Starting initial cvs checkout with "+syncuri+"..."
                        if os.path.exists(cvsdir+"/gentoo-x86"):
                                print "!!! existing",cvsdir+"/gentoo-x86 directory; exiting."
                                sys.exit(1)
                        try:
                                os.rmdir(myportdir)
                        except OSError, e:
                                if e.errno != errno.ENOENT:
                                        sys.stderr.write(
                                                "!!! existing '%s' directory; exiting.\n" % myportdir)
                                        sys.exit(1)
                                del e
                        if portage.spawn("cd "+cvsdir+"; cvs -z0 -d "+cvsroot+" co -P gentoo-x86",settings,free=1):
                                print "!!! cvs checkout error; exiting."
                                sys.exit(1)
                        os.rename(os.path.join(cvsdir, "gentoo-x86"), myportdir)
                else:
                        #cvs update
                        print ">>> Starting cvs update with "+syncuri+"..."
                        retval = portage.spawn("cd '%s'; cvs -z0 -q update -dP" % \
                                myportdir, settings, free=1)
                        if retval != os.EX_OK:
                                sys.exit(retval)
                dosyncuri = syncuri
        else:
                writemsg_level("!!! Unrecognized protocol: SYNC='%s'\n" % (syncuri,),
                        noiselevel=-1, level=logging.ERROR)
                return 1

        if updatecache_flg and  \
                myaction != "metadata" and \
                "metadata-transfer" not in settings.features:
                updatecache_flg = False

        # Reload the whole config from scratch.
        settings, trees, mtimedb = load_emerge_config(trees=trees)
        root_config = trees[settings["ROOT"]]["root_config"]
        portdb = trees[settings["ROOT"]]["porttree"].dbapi

        if os.path.exists(myportdir+"/metadata/cache") and updatecache_flg:
                action_metadata(settings, portdb, myopts)

        if portage._global_updates(trees, mtimedb["updates"]):
                mtimedb.commit()
                # Reload the whole config from scratch.
                settings, trees, mtimedb = load_emerge_config(trees=trees)
                portdb = trees[settings["ROOT"]]["porttree"].dbapi
                root_config = trees[settings["ROOT"]]["root_config"]

        mybestpv = portdb.xmatch("bestmatch-visible",
                portage.const.PORTAGE_PACKAGE_ATOM)
        mypvs = portage.best(
                trees[settings["ROOT"]]["vartree"].dbapi.match(
                portage.const.PORTAGE_PACKAGE_ATOM))

        chk_updated_cfg_files("/", settings.get("CONFIG_PROTECT","").split())

        if myaction != "metadata":
                if os.access(portage.USER_CONFIG_PATH + "/bin/post_sync", os.X_OK):
                        retval = portage.process.spawn(
                                [os.path.join(portage.USER_CONFIG_PATH, "bin", "post_sync"),
                                dosyncuri], env=settings.environ())
                        if retval != os.EX_OK:
                                print red(" * ")+bold("spawn failed of "+ portage.USER_CONFIG_PATH + "/bin/post_sync")

        if(mybestpv != mypvs) and not "--quiet" in myopts:
                print
                print red(" * ")+bold("An update to portage is available.")+" It is _highly_ recommended"
                print red(" * ")+"that you update portage now, before any other packages are updated."
                print
                print red(" * ")+"To update portage, run 'emerge portage' now."
                print
        
        display_news_notification(root_config, myopts)
        return os.EX_OK

def action_metadata(settings, portdb, myopts):
        portage.writemsg_stdout("\n>>> Updating Portage cache:      ")
        old_umask = os.umask(0002)
        cachedir = os.path.normpath(settings.depcachedir)
        if cachedir in ["/",    "/bin", "/dev",  "/etc",  "/home",
                                        "/lib", "/opt", "/proc", "/root", "/sbin",
                                        "/sys", "/tmp", "/usr",  "/var"]:
                print >> sys.stderr, "!!! PORTAGE_DEPCACHEDIR IS SET TO A PRIMARY " + \
                        "ROOT DIRECTORY ON YOUR SYSTEM."
                print >> sys.stderr, \
                        "!!! This is ALMOST CERTAINLY NOT what you want: '%s'" % cachedir
                sys.exit(73)
        if not os.path.exists(cachedir):
                os.mkdir(cachedir)

        ec = portage.eclass_cache.cache(portdb.porttree_root)
        myportdir = os.path.realpath(settings["PORTDIR"])
        cm = settings.load_best_module("portdbapi.metadbmodule")(
                myportdir, "metadata/cache", portage.auxdbkeys[:], readonly=True)

        from portage.cache import util

        class percentage_noise_maker(util.quiet_mirroring):
                def __init__(self, dbapi):
                        self.dbapi = dbapi
                        self.cp_all = dbapi.cp_all()
                        l = len(self.cp_all)
                        self.call_update_min = 100000000
                        self.min_cp_all = l/100.0
                        self.count = 1
                        self.pstr = ''

                def __iter__(self):
                        for x in self.cp_all:
                                self.count += 1
                                if self.count > self.min_cp_all:
                                        self.call_update_min = 0
                                        self.count = 0
                                for y in self.dbapi.cp_list(x):
                                        yield y
                        self.call_update_mine = 0

                def update(self, *arg):
                        try:                            self.pstr = int(self.pstr) + 1
                        except ValueError:      self.pstr = 1
                        sys.stdout.write("%s%i%%" % \
                                ("\b" * (len(str(self.pstr))+1), self.pstr))
                        sys.stdout.flush()
                        self.call_update_min = 10000000

                def finish(self, *arg):
                        sys.stdout.write("\b\b\b\b100%\n")
                        sys.stdout.flush()

        if "--quiet" in myopts:
                def quicky_cpv_generator(cp_all_list):
                        for x in cp_all_list:
                                for y in portdb.cp_list(x):
                                        yield y
                source = quicky_cpv_generator(portdb.cp_all())
                noise_maker = portage.cache.util.quiet_mirroring()
        else:
                noise_maker = source = percentage_noise_maker(portdb)
        portage.cache.util.mirror_cache(source, cm, portdb.auxdb[myportdir],
                eclass_cache=ec, verbose_instance=noise_maker)

        sys.stdout.flush()
        os.umask(old_umask)

def action_regen(settings, portdb, max_jobs, max_load):
        xterm_titles = "notitles" not in settings.features
        emergelog(xterm_titles, " === regen")
        #regenerate cache entries
        portage.writemsg_stdout("Regenerating cache entries...\n")
        try:
                os.close(sys.stdin.fileno())
        except SystemExit, e:
                raise # Needed else can't exit
        except:
                pass
        sys.stdout.flush()

        regen = MetadataRegen(portdb, max_jobs=max_jobs, max_load=max_load)
        regen.run()

        portage.writemsg_stdout("done!\n")

def action_config(settings, trees, myopts, myfiles):
        if len(myfiles) != 1:
                print red("!!! config can only take a single package atom at this time\n")
                sys.exit(1)
        if not is_valid_package_atom(myfiles[0]):
                portage.writemsg("!!! '%s' is not a valid package atom.\n" % myfiles[0],
                        noiselevel=-1)
                portage.writemsg("!!! Please check ebuild(5) for full details.\n")
                portage.writemsg("!!! (Did you specify a version but forget to prefix with '='?)\n")
                sys.exit(1)
        print
        try:
                pkgs = trees[settings["ROOT"]]["vartree"].dbapi.match(myfiles[0])
        except portage.exception.AmbiguousPackageName, e:
                # Multiple matches thrown from cpv_expand
                pkgs = e.args[0]
        if len(pkgs) == 0:
                print "No packages found.\n"
                sys.exit(0)
        elif len(pkgs) > 1:
                if "--ask" in myopts:
                        options = []
                        print "Please select a package to configure:"
                        idx = 0
                        for pkg in pkgs:
                                idx += 1
                                options.append(str(idx))
                                print options[-1]+") "+pkg
                        print "X) Cancel"
                        options.append("X")
                        idx = userquery("Selection?", options)
                        if idx == "X":
                                sys.exit(0)
                        pkg = pkgs[int(idx)-1]
                else:
                        print "The following packages available:"
                        for pkg in pkgs:
                                print "* "+pkg
                        print "\nPlease use a specific atom or the --ask option."
                        sys.exit(1)
        else:
                pkg = pkgs[0]

        print
        if "--ask" in myopts:
                if userquery("Ready to configure "+pkg+"?") == "No":
                        sys.exit(0)
        else:
                print "Configuring pkg..."
        print
        ebuildpath = trees[settings["ROOT"]]["vartree"].dbapi.findname(pkg)
        mysettings = portage.config(clone=settings)
        vardb = trees[mysettings["ROOT"]]["vartree"].dbapi
        debug = mysettings.get("PORTAGE_DEBUG") == "1"
        retval = portage.doebuild(ebuildpath, "config", mysettings["ROOT"],
                mysettings,
                debug=(settings.get("PORTAGE_DEBUG", "") == 1), cleanup=True,
                mydbapi=trees[settings["ROOT"]]["vartree"].dbapi, tree="vartree")
        if retval == os.EX_OK:
                portage.doebuild(ebuildpath, "clean", mysettings["ROOT"],
                        mysettings, debug=debug, mydbapi=vardb, tree="vartree")
        print

def action_info(settings, trees, myopts, myfiles):
        print getportageversion(settings["PORTDIR"], settings["ROOT"],
                settings.profile_path, settings["CHOST"],
                trees[settings["ROOT"]]["vartree"].dbapi)
        header_width = 65
        header_title = "System Settings"
        if myfiles:
                print header_width * "="
                print header_title.rjust(int(header_width/2 + len(header_title)/2))
        print header_width * "="
        print "System uname: "+platform.platform(aliased=1)

        lastSync = portage.grabfile(os.path.join(
                settings["PORTDIR"], "metadata", "timestamp.chk"))
        print "Timestamp of tree:",
        if lastSync:
                print lastSync[0]
        else:
                print "Unknown"

        output=commands.getstatusoutput("distcc --version")
        if not output[0]:
                print str(output[1].split("\n",1)[0]),
                if "distcc" in settings.features:
                        print "[enabled]"
                else:
                        print "[disabled]"

        output=commands.getstatusoutput("ccache -V")
        if not output[0]:
                print str(output[1].split("\n",1)[0]),
                if "ccache" in settings.features:
                        print "[enabled]"
                else:
                        print "[disabled]"

        myvars  = ["sys-devel/autoconf", "sys-devel/automake", "virtual/os-headers",
                   "sys-devel/binutils", "sys-devel/libtool",  "dev-lang/python"]
        myvars += portage.util.grabfile(settings["PORTDIR"]+"/profiles/info_pkgs")
        myvars  = portage.util.unique_array(myvars)
        myvars.sort()

        for x in myvars:
                if portage.isvalidatom(x):
                        pkg_matches = trees["/"]["vartree"].dbapi.match(x)
                        pkg_matches = [portage.catpkgsplit(cpv)[1:] for cpv in pkg_matches]
                        pkg_matches.sort(portage.pkgcmp)
                        pkgs = []
                        for pn, ver, rev in pkg_matches:
                                if rev != "r0":
                                        pkgs.append(ver + "-" + rev)
                                else:
                                        pkgs.append(ver)
                        if pkgs:
                                pkgs = ", ".join(pkgs)
                                print "%-20s %s" % (x+":", pkgs)
                else:
                        print "%-20s %s" % (x+":", "[NOT VALID]")

        libtool_vers = ",".join(trees["/"]["vartree"].dbapi.match("sys-devel/libtool"))

        if "--verbose" in myopts:
                myvars=settings.keys()
        else:
                myvars = ['GENTOO_MIRRORS', 'CONFIG_PROTECT', 'CONFIG_PROTECT_MASK',
                          'PORTDIR', 'DISTDIR', 'PKGDIR', 'PORTAGE_TMPDIR',
                          'PORTDIR_OVERLAY', 'USE', 'CHOST', 'CFLAGS', 'CXXFLAGS',
                          'ACCEPT_KEYWORDS', 'SYNC', 'FEATURES', 'EMERGE_DEFAULT_OPTS']

                myvars.extend(portage.util.grabfile(settings["PORTDIR"]+"/profiles/info_vars"))

        myvars = portage.util.unique_array(myvars)
        unset_vars = []
        myvars.sort()
        for x in myvars:
                if x in settings:
                        if x != "USE":
                                print '%s="%s"' % (x, settings[x])
                        else:
                                use = set(settings["USE"].split())
                                use_expand = settings["USE_EXPAND"].split()
                                use_expand.sort()
                                for varname in use_expand:
                                        flag_prefix = varname.lower() + "_"
                                        for f in list(use):
                                                if f.startswith(flag_prefix):
                                                        use.remove(f)
                                use = list(use)
                                use.sort()
                                print 'USE="%s"' % " ".join(use),
                                for varname in use_expand:
                                        myval = settings.get(varname)
                                        if myval:
                                                print '%s="%s"' % (varname, myval),
                                print
                else:
                        unset_vars.append(x)
        if unset_vars:
                print "Unset:  "+", ".join(unset_vars)
        print

        if "--debug" in myopts:
                for x in dir(portage):
                        module = getattr(portage, x)
                        if "cvs_id_string" in dir(module):
                                print "%s: %s" % (str(x), str(module.cvs_id_string))

        # See if we can find any packages installed matching the strings
        # passed on the command line
        mypkgs = []
        vardb = trees[settings["ROOT"]]["vartree"].dbapi
        portdb = trees[settings["ROOT"]]["porttree"].dbapi
        for x in myfiles:
                mypkgs.extend(vardb.match(x))

        # If some packages were found...
        if mypkgs:
                # Get our global settings (we only print stuff if it varies from
                # the current config)
                mydesiredvars = [ 'CHOST', 'CFLAGS', 'CXXFLAGS', 'LDFLAGS' ]
                auxkeys = mydesiredvars + [ "USE", "IUSE"]
                global_vals = {}
                pkgsettings = portage.config(clone=settings)

                for myvar in mydesiredvars:
                        global_vals[myvar] = set(settings.get(myvar, "").split())

                # Loop through each package
                # Only print settings if they differ from global settings
                header_title = "Package Settings"
                print header_width * "="
                print header_title.rjust(int(header_width/2 + len(header_title)/2))
                print header_width * "="
                from portage.output import EOutput
                out = EOutput()
                for pkg in mypkgs:
                        # Get all package specific variables
                        auxvalues = vardb.aux_get(pkg, auxkeys)
                        valuesmap = {}
                        for i in xrange(len(auxkeys)):
                                valuesmap[auxkeys[i]] = set(auxvalues[i].split())
                        diff_values = {}
                        for myvar in mydesiredvars:
                                # If the package variable doesn't match the
                                # current global variable, something has changed
                                # so set diff_found so we know to print
                                if valuesmap[myvar] != global_vals[myvar]:
                                        diff_values[myvar] = valuesmap[myvar]
                        valuesmap["IUSE"] = set(filter_iuse_defaults(valuesmap["IUSE"]))
                        valuesmap["USE"] = valuesmap["USE"].intersection(valuesmap["IUSE"])
                        pkgsettings.reset()
                        # If a matching ebuild is no longer available in the tree, maybe it
                        # would make sense to compare against the flags for the best
                        # available version with the same slot?
                        mydb = None
                        if portdb.cpv_exists(pkg):
                                mydb = portdb
                        pkgsettings.setcpv(pkg, mydb=mydb)
                        if valuesmap["IUSE"].intersection(
                                pkgsettings["PORTAGE_USE"].split()) != valuesmap["USE"]:
                                diff_values["USE"] = valuesmap["USE"]
                        # If a difference was found, print the info for
                        # this package.
                        if diff_values:
                                # Print package info
                                print "%s was built with the following:" % pkg
                                for myvar in mydesiredvars + ["USE"]:
                                        if myvar in diff_values:
                                                mylist = list(diff_values[myvar])
                                                mylist.sort()
                                                print "%s=\"%s\"" % (myvar, " ".join(mylist))
                                print
                        print ">>> Attempting to run pkg_info() for '%s'" % pkg
                        ebuildpath = vardb.findname(pkg)
                        if not ebuildpath or not os.path.exists(ebuildpath):
                                out.ewarn("No ebuild found for '%s'" % pkg)
                                continue
                        portage.doebuild(ebuildpath, "info", pkgsettings["ROOT"],
                                pkgsettings, debug=(settings.get("PORTAGE_DEBUG", "") == 1),
                                mydbapi=trees[settings["ROOT"]]["vartree"].dbapi,
                                tree="vartree")

def action_search(root_config, myopts, myfiles, spinner):
        if not myfiles:
                print "emerge: no search terms provided."
        else:
                searchinstance = search(root_config,
                        spinner, "--searchdesc" in myopts,
                        "--quiet" not in myopts, "--usepkg" in myopts,
                        "--usepkgonly" in myopts)
                for mysearch in myfiles:
                        try:
                                searchinstance.execute(mysearch)
                        except re.error, comment:
                                print "\n!!! Regular expression error in \"%s\": %s" % ( mysearch, comment )
                                sys.exit(1)
                        searchinstance.output()

def action_depclean(settings, trees, ldpath_mtimes,
        myopts, action, myfiles, spinner):
        # Kill packages that aren't explicitly merged or are required as a
        # dependency of another package. World file is explicit.

        # Global depclean or prune operations are not very safe when there are
        # missing dependencies since it's unknown how badly incomplete
        # the dependency graph is, and we might accidentally remove packages
        # that should have been pulled into the graph. On the other hand, it's
        # relatively safe to ignore missing deps when only asked to remove
        # specific packages.
        allow_missing_deps = len(myfiles) > 0

        msg = []
        msg.append("Always study the list of packages to be cleaned for any obvious\n")
        msg.append("mistakes. Packages that are part of the world set will always\n")
        msg.append("be kept.  They can be manually added to this set with\n")
        msg.append(good("`emerge --noreplace <atom>`") + ".  Packages that are listed in\n")
        msg.append("package.provided (see portage(5)) will be removed by\n")
        msg.append("depclean, even if they are part of the world set.\n")
        msg.append("\n")
        msg.append("As a safety measure, depclean will not remove any packages\n")
        msg.append("unless *all* required dependencies have been resolved.  As a\n")
        msg.append("consequence, it is often necessary to run %s\n" % \
                good("`emerge --update"))
        msg.append(good("--newuse --deep @system @world`") + \
                " prior to depclean.\n")

        if action == "depclean" and "--quiet" not in myopts and not myfiles:
                portage.writemsg_stdout("\n")
                for x in msg:
                        portage.writemsg_stdout(colorize("WARN", " * ") + x)

        xterm_titles = "notitles" not in settings.features
        myroot = settings["ROOT"]
        root_config = trees[myroot]["root_config"]
        getSetAtoms = root_config.setconfig.getSetAtoms
        vardb = trees[myroot]["vartree"].dbapi

        required_set_names = ("system", "world")
        required_sets = {}
        set_args = []

        for s in required_set_names:
                required_sets[s] = InternalPackageSet(
                        initial_atoms=getSetAtoms(s))

        
        # When removing packages, use a temporary version of world
        # which excludes packages that are intended to be eligible for
        # removal.
        world_temp_set = required_sets["world"]
        system_set = required_sets["system"]

        if not system_set or not world_temp_set:

                if not system_set:
                        writemsg_level("!!! You have no system list.\n",
                                level=logging.ERROR, noiselevel=-1)

                if not world_temp_set:
                        writemsg_level("!!! You have no world file.\n",
                                        level=logging.WARNING, noiselevel=-1)

                writemsg_level("!!! Proceeding is likely to " + \
                        "break your installation.\n",
                        level=logging.WARNING, noiselevel=-1)
                if "--pretend" not in myopts:
                        countdown(int(settings["EMERGE_WARNING_DELAY"]), ">>> Depclean")

        if action == "depclean":
                emergelog(xterm_titles, " >>> depclean")

        import textwrap
        args_set = InternalPackageSet()
        if myfiles:
                for x in myfiles:
                        if not is_valid_package_atom(x):
                                writemsg_level("!!! '%s' is not a valid package atom.\n" % x,
                                        level=logging.ERROR, noiselevel=-1)
                                writemsg_level("!!! Please check ebuild(5) for full details.\n")
                                return
                        try:
                                atom = portage.dep_expand(x, mydb=vardb, settings=settings)
                        except portage.exception.AmbiguousPackageName, e:
                                msg = "The short ebuild name \"" + x + \
                                        "\" is ambiguous.  Please specify " + \
                                        "one of the following " + \
                                        "fully-qualified ebuild names instead:"
                                for line in textwrap.wrap(msg, 70):
                                        writemsg_level("!!! %s\n" % (line,),
                                                level=logging.ERROR, noiselevel=-1)
                                for i in e[0]:
                                        writemsg_level("    %s\n" % colorize("INFORM", i),
                                                level=logging.ERROR, noiselevel=-1)
                                writemsg_level("\n", level=logging.ERROR, noiselevel=-1)
                                return
                        args_set.add(atom)
                matched_packages = False
                for x in args_set:
                        if vardb.match(x):
                                matched_packages = True
                                break
                if not matched_packages:
                        writemsg_level(">>> No packages selected for removal by %s\n" % \
                                action)
                        return

        writemsg_level("\nCalculating dependencies  ")
        resolver_params = create_depgraph_params(myopts, "remove")
        resolver = depgraph(settings, trees, myopts, resolver_params, spinner)
        vardb = resolver.trees[myroot]["vartree"].dbapi

        if action == "depclean":

                if args_set:
                        # Pull in everything that's installed but not matched
                        # by an argument atom since we don't want to clean any
                        # package if something depends on it.

                        world_temp_set.clear()
                        for pkg in vardb:
                                spinner.update()

                                try:
                                        if args_set.findAtomForPackage(pkg) is None:
                                                world_temp_set.add("=" + pkg.cpv)
                                                continue
                                except portage.exception.InvalidDependString, e:
                                        show_invalid_depstring_notice(pkg,
                                                pkg.metadata["PROVIDE"], str(e))
                                        del e
                                        world_temp_set.add("=" + pkg.cpv)
                                        continue

        elif action == "prune":

                # Pull in everything that's installed since we don't
                # to prune a package if something depends on it.
                world_temp_set.clear()
                world_temp_set.update(vardb.cp_all())

                if not args_set:

                        # Try to prune everything that's slotted.
                        for cp in vardb.cp_all():
                                if len(vardb.cp_list(cp)) > 1:
                                        args_set.add(cp)

                # Remove atoms from world that match installed packages
                # that are also matched by argument atoms, but do not remove
                # them if they match the highest installed version.
                for pkg in vardb:
                        spinner.update()
                        pkgs_for_cp = vardb.match_pkgs(pkg.cp)
                        if not pkgs_for_cp or pkg not in pkgs_for_cp:
                                raise AssertionError("package expected in matches: " + \
                                        "cp = %s, cpv = %s matches = %s" % \
                                        (pkg.cp, pkg.cpv, [str(x) for x in pkgs_for_cp]))

                        highest_version = pkgs_for_cp[-1]
                        if pkg == highest_version:
                                # pkg is the highest version
                                world_temp_set.add("=" + pkg.cpv)
                                continue

                        if len(pkgs_for_cp) <= 1:
                                raise AssertionError("more packages expected: " + \
                                        "cp = %s, cpv = %s matches = %s" % \
                                        (pkg.cp, pkg.cpv, [str(x) for x in pkgs_for_cp]))

                        try:
                                if args_set.findAtomForPackage(pkg) is None:
                                        world_temp_set.add("=" + pkg.cpv)
                                        continue
                        except portage.exception.InvalidDependString, e:
                                show_invalid_depstring_notice(pkg,
                                        pkg.metadata["PROVIDE"], str(e))
                                del e
                                world_temp_set.add("=" + pkg.cpv)
                                continue

        set_args = {}
        for s, package_set in required_sets.iteritems():
                set_atom = SETPREFIX + s
                set_arg = SetArg(arg=set_atom, set=package_set,
                        root_config=resolver.roots[myroot])
                set_args[s] = set_arg
                for atom in set_arg.set:
                        resolver._dep_stack.append(
                                Dependency(atom=atom, root=myroot, parent=set_arg))
                        resolver.digraph.add(set_arg, None)

        success = resolver._complete_graph()
        writemsg_level("\b\b... done!\n")

        resolver.display_problems()

        if not success:
                return 1

        def unresolved_deps():

                unresolvable = set()
                for dep in resolver._initially_unsatisfied_deps:
                        if isinstance(dep.parent, Package) and \
                                (dep.priority > UnmergeDepPriority.SOFT):
                                unresolvable.add((dep.atom, dep.parent.cpv))

                if not unresolvable:
                        return False

                if unresolvable and not allow_missing_deps:
                        prefix = bad(" * ")
                        msg = []
                        msg.append("Dependencies could not be completely resolved due to")
                        msg.append("the following required packages not being installed:")
                        msg.append("")
                        for atom, parent in unresolvable:
                                msg.append("  %s pulled in by:" % (atom,))
                                msg.append("    %s" % (parent,))
                                msg.append("")
                        msg.append("Have you forgotten to run " + \
                                good("`emerge --update --newuse --deep world`") + " prior to")
                        msg.append(("%s?  It may be necessary to manually " + \
                                "uninstall packages that no longer") % action)
                        msg.append("exist in the portage tree since " + \
                                "it may not be possible to satisfy their")
                        msg.append("dependencies.  Also, be aware of " + \
                                "the --with-bdeps option that is documented")
                        msg.append("in " + good("`man emerge`") + ".")
                        if action == "prune":
                                msg.append("")
                                msg.append("If you would like to ignore " + \
                                        "dependencies then use %s." % good("--nodeps"))
                        writemsg_level("".join("%s%s\n" % (prefix, line) for line in msg),
                                level=logging.ERROR, noiselevel=-1)
                        return True
                return False

        if unresolved_deps():
                return 1

        graph = resolver.digraph.copy()
        required_pkgs_total = 0
        for node in graph:
                if isinstance(node, Package):
                        required_pkgs_total += 1

        def show_parents(child_node):
                parent_nodes = graph.parent_nodes(child_node)
                if not parent_nodes:
                        # With --prune, the highest version can be pulled in without any
                        # real parent since all installed packages are pulled in.  In that
                        # case there's nothing to show here.
                        return
                parent_strs = []
                for node in parent_nodes:
                        parent_strs.append(str(getattr(node, "cpv", node)))
                parent_strs.sort()
                msg = []
                msg.append("  %s pulled in by:\n" % (child_node.cpv,))
                for parent_str in parent_strs:
                        msg.append("    %s\n" % (parent_str,))
                msg.append("\n")
                portage.writemsg_stdout("".join(msg), noiselevel=-1)

        def create_cleanlist():
                pkgs_to_remove = []

                if action == "depclean":
                        if args_set:

                                for pkg in vardb:
                                        arg_atom = None
                                        try:
                                                arg_atom = args_set.findAtomForPackage(pkg)
                                        except portage.exception.InvalidDependString:
                                                # this error has already been displayed by now
                                                continue

                                        if arg_atom:
                                                if pkg not in graph:
                                                        pkgs_to_remove.append(pkg)
                                                elif "--verbose" in myopts:
                                                        show_parents(pkg)

                        else:
                                for pkg in vardb:
                                        if pkg not in graph:
                                                pkgs_to_remove.append(pkg)
                                        elif "--verbose" in myopts:
                                                show_parents(pkg)

                elif action == "prune":
                        # Prune really uses all installed instead of world. It's not
                        # a real reverse dependency so don't display it as such.
                        graph.remove(set_args["world"])

                        for atom in args_set:
                                for pkg in vardb.match_pkgs(atom):
                                        if pkg not in graph:
                                                pkgs_to_remove.append(pkg)
                                        elif "--verbose" in myopts:
                                                show_parents(pkg)

                if not pkgs_to_remove:
                        writemsg_level(
                                ">>> No packages selected for removal by %s\n" % action)
                        if "--verbose" not in myopts:
                                writemsg_level(
                                        ">>> To see reverse dependencies, use %s\n" % \
                                                good("--verbose"))
                        if action == "prune":
                                writemsg_level(
                                        ">>> To ignore dependencies, use %s\n" % \
                                                good("--nodeps"))

                return pkgs_to_remove

        cleanlist = create_cleanlist()

        if len(cleanlist):
                clean_set = set(cleanlist)

                # Check if any of these package are the sole providers of libraries
                # with consumers that have not been selected for removal. If so, these
                # packages and any dependencies need to be added to the graph.
                real_vardb = trees[myroot]["vartree"].dbapi
                linkmap = real_vardb.linkmap
                liblist = linkmap.listLibraryObjects()
                consumer_cache = {}
                provider_cache = {}
                soname_cache = {}
                consumer_map = {}

                writemsg_level(">>> Checking for lib consumers...\n")

                for pkg in cleanlist:
                        pkg_dblink = real_vardb._dblink(pkg.cpv)
                        provided_libs = set()

                        for lib in liblist:
                                if pkg_dblink.isowner(lib, myroot):
                                        provided_libs.add(lib)

                        if not provided_libs:
                                continue

                        consumers = {}
                        for lib in provided_libs:
                                lib_consumers = consumer_cache.get(lib)
                                if lib_consumers is None:
                                        lib_consumers = linkmap.findConsumers(lib)
                                        consumer_cache[lib] = lib_consumers
                                if lib_consumers:
                                        consumers[lib] = lib_consumers

                        if not consumers:
                                continue

                        for lib, lib_consumers in consumers.items():
                                for consumer_file in list(lib_consumers):
                                        if pkg_dblink.isowner(consumer_file, myroot):
                                                lib_consumers.remove(consumer_file)
                                if not lib_consumers:
                                        del consumers[lib]

                        if not consumers:
                                continue

                        for lib, lib_consumers in consumers.iteritems():

                                soname = soname_cache.get(lib)
                                if soname is None:
                                        soname = linkmap.getSoname(lib)
                                        soname_cache[lib] = soname

                                consumer_providers = []
                                for lib_consumer in lib_consumers:
                                        providers = provider_cache.get(lib)
                                        if providers is None:
                                                providers = linkmap.findProviders(lib_consumer)
                                                provider_cache[lib_consumer] = providers
                                        if soname not in providers:
                                                # Why does this happen?
                                                continue
                                        consumer_providers.append(
                                                (lib_consumer, providers[soname]))

                                consumers[lib] = consumer_providers

                        consumer_map[pkg] = consumers

                if consumer_map:

                        search_files = set()
                        for consumers in consumer_map.itervalues():
                                for lib, consumer_providers in consumers.iteritems():
                                        for lib_consumer, providers in consumer_providers:
                                                search_files.add(lib_consumer)
                                                search_files.update(providers)

                        writemsg_level(">>> Assigning files to packages...\n")
                        file_owners = real_vardb._owners.getFileOwnerMap(search_files)

                        for pkg, consumers in consumer_map.items():
                                for lib, consumer_providers in consumers.items():
                                        lib_consumers = set()

                                        for lib_consumer, providers in consumer_providers:
                                                owner_set = file_owners.get(lib_consumer)
                                                provider_dblinks = set()
                                                provider_pkgs = set()

                                                if len(providers) > 1:
                                                        for provider in providers:
                                                                provider_set = file_owners.get(provider)
                                                                if provider_set is not None:
                                                                        provider_dblinks.update(provider_set)

                                                if len(provider_dblinks) > 1:
                                                        for provider_dblink in provider_dblinks:
                                                                pkg_key = ("installed", myroot,
                                                                        provider_dblink.mycpv, "nomerge")
                                                                if pkg_key not in clean_set:
                                                                        provider_pkgs.add(vardb.get(pkg_key))

                                                if provider_pkgs:
                                                        continue

                                                if owner_set is not None:
                                                        lib_consumers.update(owner_set)

                                        for consumer_dblink in list(lib_consumers):
                                                if ("installed", myroot, consumer_dblink.mycpv,
                                                        "nomerge") in clean_set:
                                                        lib_consumers.remove(consumer_dblink)
                                                        continue

                                        if lib_consumers:
                                                consumers[lib] = lib_consumers
                                        else:
                                                del consumers[lib]
                                if not consumers:
                                        del consumer_map[pkg]

                if consumer_map:
                        # TODO: Implement a package set for rebuilding consumer packages.

                        msg = "In order to avoid breakage of link level " + \
                                "dependencies, one or more packages will not be removed. " + \
                                "This can be solved by rebuilding " + \
                                "the packages that pulled them in."

                        prefix = bad(" * ")
                        from textwrap import wrap
                        writemsg_level("".join(prefix + "%s\n" % line for \
                                line in wrap(msg, 70)), level=logging.WARNING, noiselevel=-1)

                        msg = []
                        for pkg, consumers in consumer_map.iteritems():
                                unique_consumers = set(chain(*consumers.values()))
                                unique_consumers = sorted(consumer.mycpv \
                                        for consumer in unique_consumers)
                                msg.append("")
                                msg.append("  %s pulled in by:" % (pkg.cpv,))
                                for consumer in unique_consumers:
                                        msg.append("    %s" % (consumer,))
                        msg.append("")
                        writemsg_level("".join(prefix + "%s\n" % line for line in msg),
                                level=logging.WARNING, noiselevel=-1)

                        # Add lib providers to the graph as children of lib consumers,
                        # and also add any dependencies pulled in by the provider.
                        writemsg_level(">>> Adding lib providers to graph...\n")

                        for pkg, consumers in consumer_map.iteritems():
                                for consumer_dblink in set(chain(*consumers.values())):
                                        consumer_pkg = vardb.get(("installed", myroot,
                                                consumer_dblink.mycpv, "nomerge"))
                                        if not resolver._add_pkg(pkg,
                                                Dependency(parent=consumer_pkg,
                                                priority=UnmergeDepPriority(runtime=True),
                                                root=pkg.root)):
                                                resolver.display_problems()
                                                return 1

                        writemsg_level("\nCalculating dependencies  ")
                        success = resolver._complete_graph()
                        writemsg_level("\b\b... done!\n")
                        resolver.display_problems()
                        if not success:
                                return 1
                        if unresolved_deps():
                                return 1

                        graph = resolver.digraph.copy()
                        required_pkgs_total = 0
                        for node in graph:
                                if isinstance(node, Package):
                                        required_pkgs_total += 1
                        cleanlist = create_cleanlist()
                        if not cleanlist:
                                return 0
                        clean_set = set(cleanlist)

                # Use a topological sort to create an unmerge order such that
                # each package is unmerged before it's dependencies. This is
                # necessary to avoid breaking things that may need to run
                # during pkg_prerm or pkg_postrm phases.

                # Create a new graph to account for dependencies between the
                # packages being unmerged.
                graph = digraph()
                del cleanlist[:]

                dep_keys = ["DEPEND", "RDEPEND", "PDEPEND"]
                runtime = UnmergeDepPriority(runtime=True)
                runtime_post = UnmergeDepPriority(runtime_post=True)
                buildtime = UnmergeDepPriority(buildtime=True)
                priority_map = {
                        "RDEPEND": runtime,
                        "PDEPEND": runtime_post,
                        "DEPEND": buildtime,
                }

                for node in clean_set:
                        graph.add(node, None)
                        mydeps = []
                        node_use = node.metadata["USE"].split()
                        for dep_type in dep_keys:
                                depstr = node.metadata[dep_type]
                                if not depstr:
                                        continue
                                try:
                                        portage.dep._dep_check_strict = False
                                        success, atoms = portage.dep_check(depstr, None, settings,
                                                myuse=node_use, trees=resolver._graph_trees,
                                                myroot=myroot)
                                finally:
                                        portage.dep._dep_check_strict = True
                                if not success:
                                        # Ignore invalid deps of packages that will
                                        # be uninstalled anyway.
                                        continue

                                priority = priority_map[dep_type]
                                for atom in atoms:
                                        if not isinstance(atom, portage.dep.Atom):
                                                # Ignore invalid atoms returned from dep_check().
                                                continue
                                        if atom.blocker:
                                                continue
                                        matches = vardb.match_pkgs(atom)
                                        if not matches:
                                                continue
                                        for child_node in matches:
                                                if child_node in clean_set:
                                                        graph.add(child_node, node, priority=priority)

                ordered = True
                if len(graph.order) == len(graph.root_nodes()):
                        # If there are no dependencies between packages
                        # let unmerge() group them by cat/pn.
                        ordered = False
                        cleanlist = [pkg.cpv for pkg in graph.order]
                else:
                        # Order nodes from lowest to highest overall reference count for
                        # optimal root node selection.
                        node_refcounts = {}
                        for node in graph.order:
                                node_refcounts[node] = len(graph.parent_nodes(node))
                        def cmp_reference_count(node1, node2):
                                return node_refcounts[node1] - node_refcounts[node2]
                        graph.order.sort(cmp_reference_count)
        
                        ignore_priority_range = [None]
                        ignore_priority_range.extend(
                                xrange(UnmergeDepPriority.MIN, UnmergeDepPriority.MAX + 1))
                        while not graph.empty():
                                for ignore_priority in ignore_priority_range:
                                        nodes = graph.root_nodes(ignore_priority=ignore_priority)
                                        if nodes:
                                                break
                                if not nodes:
                                        raise AssertionError("no root nodes")
                                if ignore_priority is not None:
                                        # Some deps have been dropped due to circular dependencies,
                                        # so only pop one node in order do minimize the number that
                                        # are dropped.
                                        del nodes[1:]
                                for node in nodes:
                                        graph.remove(node)
                                        cleanlist.append(node.cpv)

                unmerge(root_config, myopts, "unmerge", cleanlist,
                        ldpath_mtimes, ordered=ordered)

        if action == "prune":
                return

        if not cleanlist and "--quiet" in myopts:
                return

        print "Packages installed:   "+str(len(vardb.cpv_all()))
        print "Packages in world:    " + \
                str(len(root_config.sets["world"].getAtoms()))
        print "Packages in system:   " + \
                str(len(root_config.sets["system"].getAtoms()))
        print "Required packages:    "+str(required_pkgs_total)
        if "--pretend" in myopts:
                print "Number to remove:     "+str(len(cleanlist))
        else:
                print "Number removed:       "+str(len(cleanlist))

def resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner,
        skip_masked=False, skip_unsatisfied=False):
        """
        Construct a depgraph for the given resume list. This will raise
        PackageNotFound or depgraph.UnsatisfiedResumeDep when necessary.
        @rtype: tuple
        @returns: (success, depgraph, dropped_tasks)
        """
        mergelist = mtimedb["resume"]["mergelist"]
        dropped_tasks = set()
        while True:
                mydepgraph = depgraph(settings, trees,
                        myopts, myparams, spinner)
                try:
                        success = mydepgraph.loadResumeCommand(mtimedb["resume"],
                                skip_masked=skip_masked)
                except depgraph.UnsatisfiedResumeDep, e:
                        if not skip_unsatisfied:
                                raise

                        graph = mydepgraph.digraph
                        unsatisfied_parents = dict((dep.parent, dep.parent) \
                                for dep in e.value)
                        traversed_nodes = set()
                        unsatisfied_stack = list(unsatisfied_parents)
                        while unsatisfied_stack:
                                pkg = unsatisfied_stack.pop()
                                if pkg in traversed_nodes:
                                        continue
                                traversed_nodes.add(pkg)

                                # If this package was pulled in by a parent
                                # package scheduled for merge, removing this
                                # package may cause the the parent package's
                                # dependency to become unsatisfied.
                                for parent_node in graph.parent_nodes(pkg):
                                        if not isinstance(parent_node, Package) \
                                                or parent_node.operation not in ("merge", "nomerge"):
                                                continue
                                        unsatisfied = \
                                                graph.child_nodes(parent_node,
                                                ignore_priority=DepPriority.SOFT)
                                        if pkg in unsatisfied:
                                                unsatisfied_parents[parent_node] = parent_node
                                                unsatisfied_stack.append(parent_node)

                        pruned_mergelist = [x for x in mergelist \
                                if isinstance(x, list) and \
                                tuple(x) not in unsatisfied_parents]

                        # If the mergelist doesn't shrink then this loop is infinite.
                        if len(pruned_mergelist) == len(mergelist):
                                # This happens if a package can't be dropped because
                                # it's already installed, but it has unsatisfied PDEPEND.
                                raise
                        mergelist[:] = pruned_mergelist

                        # Exclude installed packages that have been removed from the graph due
                        # to failure to build/install runtime dependencies after the dependent
                        # package has already been installed.
                        dropped_tasks.update(pkg for pkg in \
                                unsatisfied_parents if pkg.operation != "nomerge")
                        mydepgraph.break_refs(unsatisfied_parents)

                        del e, graph, traversed_nodes, \
                                unsatisfied_parents, unsatisfied_stack
                        continue
                else:
                        break
        return (success, mydepgraph, dropped_tasks)

def action_build(settings, trees, mtimedb,
        myopts, myaction, myfiles, spinner):

        # validate the state of the resume data
        # so that we can make assumptions later.
        for k in ("resume", "resume_backup"):
                if k not in mtimedb:
                        continue
                resume_data = mtimedb[k]
                if not isinstance(resume_data, dict):
                        del mtimedb[k]
                        continue
                mergelist = resume_data.get("mergelist")
                if not isinstance(mergelist, list):
                        del mtimedb[k]
                        continue
                resume_opts = resume_data.get("myopts")
                if not isinstance(resume_opts, (dict, list)):
                        del mtimedb[k]
                        continue
                favorites = resume_data.get("favorites")
                if not isinstance(favorites, list):
                        del mtimedb[k]
                        continue

        resume = False
        if "--resume" in myopts and \
                ("resume" in mtimedb or
                "resume_backup" in mtimedb):
                resume = True
                if "resume" not in mtimedb:
                        mtimedb["resume"] = mtimedb["resume_backup"]
                        del mtimedb["resume_backup"]
                        mtimedb.commit()
                # "myopts" is a list for backward compatibility.
                resume_opts = mtimedb["resume"].get("myopts", [])
                if isinstance(resume_opts, list):
                        resume_opts = dict((k,True) for k in resume_opts)
                for opt in ("--skipfirst", "--ask", "--tree"):
                        resume_opts.pop(opt, None)
                myopts.update(resume_opts)

                if "--debug" in myopts:
                        writemsg_level("myopts %s\n" % (myopts,))

                # Adjust config according to options of the command being resumed.
                for myroot in trees:
                        mysettings =  trees[myroot]["vartree"].settings
                        mysettings.unlock()
                        adjust_config(myopts, mysettings)
                        mysettings.lock()
                        del myroot, mysettings

        ldpath_mtimes = mtimedb["ldpath"]
        favorites=[]
        merge_count = 0
        buildpkgonly = "--buildpkgonly" in myopts
        pretend = "--pretend" in myopts
        fetchonly = "--fetchonly" in myopts or "--fetch-all-uri" in myopts
        ask = "--ask" in myopts
        nodeps = "--nodeps" in myopts
        oneshot = "--oneshot" in myopts or "--onlydeps" in myopts
        tree = "--tree" in myopts
        if nodeps and tree:
                tree = False
                del myopts["--tree"]
                portage.writemsg(colorize("WARN", " * ") + \
                        "--tree is broken with --nodeps. Disabling...\n")
        debug = "--debug" in myopts
        verbose = "--verbose" in myopts
        quiet = "--quiet" in myopts
        if pretend or fetchonly:
                # make the mtimedb readonly
                mtimedb.filename = None
        if "--digest" in myopts:
                msg = "The --digest option can prevent corruption from being" + \
                        " noticed. The `repoman manifest` command is the preferred" + \
                        " way to generate manifests and it is capable of doing an" + \
                        " entire repository or category at once."
                prefix = bad(" * ")
                writemsg(prefix + "\n")
                from textwrap import wrap
                for line in wrap(msg, 72):
                        writemsg("%s%s\n" % (prefix, line))
                writemsg(prefix + "\n")

        if "--quiet" not in myopts and \
                ("--pretend" in myopts or "--ask" in myopts or \
                "--tree" in myopts or "--verbose" in myopts):
                action = ""
                if "--fetchonly" in myopts or "--fetch-all-uri" in myopts:
                        action = "fetched"
                elif "--buildpkgonly" in myopts:
                        action = "built"
                else:
                        action = "merged"
                if "--tree" in myopts and action != "fetched": # Tree doesn't work with fetching
                        print
                        print darkgreen("These are the packages that would be %s, in reverse order:") % action
                        print
                else:
                        print
                        print darkgreen("These are the packages that would be %s, in order:") % action
                        print

        show_spinner = "--quiet" not in myopts and "--nodeps" not in myopts
        if not show_spinner:
                spinner.update = spinner.update_quiet

        if resume:
                favorites = mtimedb["resume"].get("favorites")
                if not isinstance(favorites, list):
                        favorites = []

                if show_spinner:
                        print "Calculating dependencies  ",
                myparams = create_depgraph_params(myopts, myaction)

                resume_data = mtimedb["resume"]
                mergelist = resume_data["mergelist"]
                if mergelist and "--skipfirst" in myopts:
                        for i, task in enumerate(mergelist):
                                if isinstance(task, list) and \
                                        task and task[-1] == "merge":
                                        del mergelist[i]
                                        break

                skip_masked      = "--skipfirst" in myopts
                skip_unsatisfied = "--skipfirst" in myopts
                success = False
                mydepgraph = None
                try:
                        success, mydepgraph, dropped_tasks = resume_depgraph(
                                settings, trees, mtimedb, myopts, myparams, spinner,
                                skip_masked=skip_masked, skip_unsatisfied=skip_unsatisfied)
                except (portage.exception.PackageNotFound,
                        depgraph.UnsatisfiedResumeDep), e:
                        if isinstance(e, depgraph.UnsatisfiedResumeDep):
                                mydepgraph = e.depgraph
                        if show_spinner:
                                print
                        from textwrap import wrap
                        from portage.output import EOutput
                        out = EOutput()

                        resume_data = mtimedb["resume"]
                        mergelist = resume_data.get("mergelist")
                        if not isinstance(mergelist, list):
                                mergelist = []
                        if mergelist and debug or (verbose and not quiet):
                                out.eerror("Invalid resume list:")
                                out.eerror("")
                                indent = "  "
                                for task in mergelist:
                                        if isinstance(task, list):
                                                out.eerror(indent + str(tuple(task)))
                                out.eerror("")

                        if isinstance(e, depgraph.UnsatisfiedResumeDep):
                                out.eerror("One or more packages are either masked or " + \
                                        "have missing dependencies:")
                                out.eerror("")
                                indent = "  "
                                for dep in e.value:
                                        if dep.atom is None:
                                                out.eerror(indent + "Masked package:")
                                                out.eerror(2 * indent + str(dep.parent))
                                                out.eerror("")
                                        else:
                                                out.eerror(indent + str(dep.atom) + " pulled in by:")
                                                out.eerror(2 * indent + str(dep.parent))
                                                out.eerror("")
                                msg = "The resume list contains packages " + \
                                        "that are either masked or have " + \
                                        "unsatisfied dependencies. " + \
                                        "Please restart/continue " + \
                                        "the operation manually, or use --skipfirst " + \
                                        "to skip the first package in the list and " + \
                                        "any other packages that may be " + \
                                        "masked or have missing dependencies."
                                for line in wrap(msg, 72):
                                        out.eerror(line)
                        elif isinstance(e, portage.exception.PackageNotFound):
                                out.eerror("An expected package is " + \
                                        "not available: %s" % str(e))
                                out.eerror("")
                                msg = "The resume list contains one or more " + \
                                        "packages that are no longer " + \
                                        "available. Please restart/continue " + \
                                        "the operation manually."
                                for line in wrap(msg, 72):
                                        out.eerror(line)
                else:
                        if show_spinner:
                                print "\b\b... done!"

                if success:
                        if dropped_tasks:
                                portage.writemsg("!!! One or more packages have been " + \
                                        "dropped due to\n" + \
                                        "!!! masking or unsatisfied dependencies:\n\n",
                                        noiselevel=-1)
                                for task in dropped_tasks:
                                        portage.writemsg("  " + str(task) + "\n", noiselevel=-1)
                                portage.writemsg("\n", noiselevel=-1)
                        del dropped_tasks
                else:
                        if mydepgraph is not None:
                                mydepgraph.display_problems()
                        if not (ask or pretend):
                                # delete the current list and also the backup
                                # since it's probably stale too.
                                for k in ("resume", "resume_backup"):
                                        mtimedb.pop(k, None)
                                mtimedb.commit()

                        return 1
        else:
                if ("--resume" in myopts):
                        print darkgreen("emerge: It seems we have nothing to resume...")
                        return os.EX_OK

                myparams = create_depgraph_params(myopts, myaction)
                if "--quiet" not in myopts and "--nodeps" not in myopts:
                        print "Calculating dependencies  ",
                        sys.stdout.flush()
                mydepgraph = depgraph(settings, trees, myopts, myparams, spinner)
                try:
                        retval, favorites = mydepgraph.select_files(myfiles)
                except portage.exception.PackageNotFound, e:
                        portage.writemsg("\n!!! %s\n" % str(e), noiselevel=-1)
                        return 1
                except portage.exception.PackageSetNotFound, e:
                        root_config = trees[settings["ROOT"]]["root_config"]
                        display_missing_pkg_set(root_config, e.value)
                        return 1
                if show_spinner:
                        print "\b\b... done!"
                if not retval:
                        mydepgraph.display_problems()
                        return 1

        if "--pretend" not in myopts and \
                ("--ask" in myopts or "--tree" in myopts or \
                "--verbose" in myopts) and \
                not ("--quiet" in myopts and "--ask" not in myopts):
                if "--resume" in myopts:
                        mymergelist = mydepgraph.altlist()
                        if len(mymergelist) == 0:
                                print colorize("INFORM", "emerge: It seems we have nothing to resume...")
                                return os.EX_OK
                        favorites = mtimedb["resume"]["favorites"]
                        retval = mydepgraph.display(
                                mydepgraph.altlist(reversed=tree),
                                favorites=favorites)
                        mydepgraph.display_problems()
                        if retval != os.EX_OK:
                                return retval
                        prompt="Would you like to resume merging these packages?"
                else:
                        retval = mydepgraph.display(
                                mydepgraph.altlist(reversed=("--tree" in myopts)),
                                favorites=favorites)
                        mydepgraph.display_problems()
                        if retval != os.EX_OK:
                                return retval
                        mergecount=0
                        for x in mydepgraph.altlist():
                                if isinstance(x, Package) and x.operation == "merge":
                                        mergecount += 1

                        if mergecount==0:
                                sets = trees[settings["ROOT"]]["root_config"].sets
                                world_candidates = None
                                if "--noreplace" in myopts and \
                                        not oneshot and favorites:
                                        # Sets that are not world candidates are filtered
                                        # out here since the favorites list needs to be
                                        # complete for depgraph.loadResumeCommand() to
                                        # operate correctly.
                                        world_candidates = [x for x in favorites \
                                                if not (x.startswith(SETPREFIX) and \
                                                not sets[x[1:]].world_candidate)]
                                if "--noreplace" in myopts and \
                                        not oneshot and world_candidates:
                                        print
                                        for x in world_candidates:
                                                print " %s %s" % (good("*"), x)
                                        prompt="Would you like to add these packages to your world favorites?"
                                elif settings["AUTOCLEAN"] and "yes"==settings["AUTOCLEAN"]:
                                        prompt="Nothing to merge; would you like to auto-clean packages?"
                                else:
                                        print
                                        print "Nothing to merge; quitting."
                                        print
                                        return os.EX_OK
                        elif "--fetchonly" in myopts or "--fetch-all-uri" in myopts:
                                prompt="Would you like to fetch the source files for these packages?"
                        else:
                                prompt="Would you like to merge these packages?"
                print
                if "--ask" in myopts and userquery(prompt) == "No":
                        print
                        print "Quitting."
                        print
                        return os.EX_OK
                # Don't ask again (e.g. when auto-cleaning packages after merge)
                myopts.pop("--ask", None)

        if ("--pretend" in myopts) and not ("--fetchonly" in myopts or "--fetch-all-uri" in myopts):
                if ("--resume" in myopts):
                        mymergelist = mydepgraph.altlist()
                        if len(mymergelist) == 0:
                                print colorize("INFORM", "emerge: It seems we have nothing to resume...")
                                return os.EX_OK
                        favorites = mtimedb["resume"]["favorites"]
                        retval = mydepgraph.display(
                                mydepgraph.altlist(reversed=tree),
                                favorites=favorites)
                        mydepgraph.display_problems()
                        if retval != os.EX_OK:
                                return retval
                else:
                        retval = mydepgraph.display(
                                mydepgraph.altlist(reversed=("--tree" in myopts)),
                                favorites=favorites)
                        mydepgraph.display_problems()
                        if retval != os.EX_OK:
                                return retval
                        if "--buildpkgonly" in myopts:
                                graph_copy = mydepgraph.digraph.clone()
                                for node in list(graph_copy.order):
                                        if not isinstance(node, Package):
                                                graph_copy.remove(node)
                                if not graph_copy.hasallzeros(ignore_priority=DepPriority.MEDIUM):
                                        print "\n!!! --buildpkgonly requires all dependencies to be merged."
                                        print "!!! You have to merge the dependencies before you can build this package.\n"
                                        return 1
        else:
                if "--buildpkgonly" in myopts:
                        graph_copy = mydepgraph.digraph.clone()
                        for node in list(graph_copy.order):
                                if not isinstance(node, Package):
                                        graph_copy.remove(node)
                        if not graph_copy.hasallzeros(ignore_priority=DepPriority.MEDIUM):
                                print "\n!!! --buildpkgonly requires all dependencies to be merged."
                                print "!!! Cannot merge requested packages. Merge deps and try again.\n"
                                return 1

                if ("--resume" in myopts):
                        favorites=mtimedb["resume"]["favorites"]
                        mymergelist = mydepgraph.altlist()
                        mydepgraph.break_refs(mymergelist)
                        mergetask = Scheduler(settings, trees, mtimedb, myopts,
                                spinner, mymergelist, favorites, mydepgraph.schedulerGraph())
                        del mydepgraph, mymergelist
                        clear_caches(trees)

                        retval = mergetask.merge()
                        merge_count = mergetask.curval
                else:
                        if "resume" in mtimedb and \
                        "mergelist" in mtimedb["resume"] and \
                        len(mtimedb["resume"]["mergelist"]) > 1:
                                mtimedb["resume_backup"] = mtimedb["resume"]
                                del mtimedb["resume"]
                                mtimedb.commit()
                        mtimedb["resume"]={}
                        # Stored as a dict starting with portage-2.2_rc7, and supported
                        # by >=portage-2.1.3_rc8. Versions <portage-2.1.3_rc8 only support
                        # a list type for options.
                        mtimedb["resume"]["myopts"] = myopts.copy()

                        # Convert Atom instances to plain str since the mtimedb loader
                        # sets unpickler.find_global = None which causes unpickler.load()
                        # to raise the following exception:
                        #
                        # cPickle.UnpicklingError: Global and instance pickles are not supported.
                        #
                        # TODO: Maybe stop setting find_global = None, or find some other
                        # way to avoid accidental triggering of the above UnpicklingError.
                        mtimedb["resume"]["favorites"] = [str(x) for x in favorites]

                        if ("--digest" in myopts) and not ("--fetchonly" in myopts or "--fetch-all-uri" in myopts):
                                for pkgline in mydepgraph.altlist():
                                        if pkgline[0]=="ebuild" and pkgline[3]=="merge":
                                                y = trees[pkgline[1]]["porttree"].dbapi.findname(pkgline[2])
                                                tmpsettings = portage.config(clone=settings)
                                                edebug = 0
                                                if settings.get("PORTAGE_DEBUG", "") == "1":
                                                        edebug = 1
                                                retval = portage.doebuild(
                                                        y, "digest", settings["ROOT"], tmpsettings, edebug,
                                                        ("--pretend" in myopts),
                                                        mydbapi=trees[pkgline[1]]["porttree"].dbapi,
                                                        tree="porttree")

                        pkglist = mydepgraph.altlist()
                        mydepgraph.saveNomergeFavorites()
                        mydepgraph.break_refs(pkglist)
                        mergetask = Scheduler(settings, trees, mtimedb, myopts,
                                spinner, pkglist, favorites, mydepgraph.schedulerGraph())
                        del mydepgraph, pkglist
                        clear_caches(trees)

                        retval = mergetask.merge()
                        merge_count = mergetask.curval

                if retval == os.EX_OK and not (buildpkgonly or fetchonly or pretend):
                        if "yes" == settings.get("AUTOCLEAN"):
                                portage.writemsg_stdout(">>> Auto-cleaning packages...\n")
                                unmerge(trees[settings["ROOT"]]["root_config"],
                                        myopts, "clean", [],
                                        ldpath_mtimes, autoclean=1)
                        else:
                                portage.writemsg_stdout(colorize("WARN", "WARNING:")
                                        + " AUTOCLEAN is disabled.  This can cause serious"
                                        + " problems due to overlapping packages.\n")
                        trees[settings["ROOT"]]["vartree"].dbapi.plib_registry.pruneNonExisting()

                return retval

def multiple_actions(action1, action2):
        sys.stderr.write("\n!!! Multiple actions requested... Please choose one only.\n")
        sys.stderr.write("!!! '%s' or '%s'\n\n" % (action1, action2))
        sys.exit(1)

def insert_optional_args(args):
        """
        Parse optional arguments and insert a value if one has
        not been provided. This is done before feeding the args
        to the optparse parser since that parser does not support
        this feature natively.
        """

        new_args = []
        jobs_opts = ("-j", "--jobs")
        arg_stack = args[:]
        arg_stack.reverse()
        while arg_stack:
                arg = arg_stack.pop()

                short_job_opt = bool("j" in arg and arg[:1] == "-" and arg[:2] != "--")
                if not (short_job_opt or arg in jobs_opts):
                        new_args.append(arg)
                        continue

                # Insert an empty placeholder in order to
                # satisfy the requirements of optparse.

                new_args.append("--jobs")
                job_count = None
                saved_opts = None
                if short_job_opt and len(arg) > 2:
                        if arg[:2] == "-j":
                                try:
                                        job_count = int(arg[2:])
                                except ValueError:
                                        saved_opts = arg[2:]
                        else:
                                job_count = "True"
                                saved_opts = arg[1:].replace("j", "")

                if job_count is None and arg_stack:
                        try:
                                job_count = int(arg_stack[-1])
                        except ValueError:
                                pass
                        else:
                                # Discard the job count from the stack
                                # since we're consuming it here.
                                arg_stack.pop()

                if job_count is None:
                        # unlimited number of jobs
                        new_args.append("True")
                else:
                        new_args.append(str(job_count))

                if saved_opts is not None:
                        new_args.append("-" + saved_opts)

        return new_args

def parse_opts(tmpcmdline, silent=False):
        myaction=None
        myopts = {}
        myfiles=[]

        global actions, options, shortmapping

        longopt_aliases = {"--cols":"--columns", "--skip-first":"--skipfirst"}
        argument_options = {
                "--config-root": {
                        "help":"specify the location for portage configuration files",
                        "action":"store"
                },
                "--color": {
                        "help":"enable or disable color output",
                        "type":"choice",
                        "choices":("y", "n")
                },

                "--jobs": {

                        "help"   : "Specifies the number of packages to build " + \
                                "simultaneously.",

                        "action" : "store"
                },

                "--load-average": {

                        "help"   :"Specifies that no new builds should be started " + \
                                "if there are other builds running and the load average " + \
                                "is at least LOAD (a floating-point number).",

                        "action" : "store"
                },

                "--with-bdeps": {
                        "help":"include unnecessary build time dependencies",
                        "type":"choice",
                        "choices":("y", "n")
                },
                "--reinstall": {
                        "help":"specify conditions to trigger package reinstallation",
                        "type":"choice",
                        "choices":["changed-use"]
                }
        }

        from optparse import OptionParser
        parser = OptionParser()
        if parser.has_option("--help"):
                parser.remove_option("--help")

        for action_opt in actions:
                parser.add_option("--" + action_opt, action="store_true",
                        dest=action_opt.replace("-", "_"), default=False)
        for myopt in options:
                parser.add_option(myopt, action="store_true",
                        dest=myopt.lstrip("--").replace("-", "_"), default=False)
        for shortopt, longopt in shortmapping.iteritems():
                parser.add_option("-" + shortopt, action="store_true",
                        dest=longopt.lstrip("--").replace("-", "_"), default=False)
        for myalias, myopt in longopt_aliases.iteritems():
                parser.add_option(myalias, action="store_true",
                        dest=myopt.lstrip("--").replace("-", "_"), default=False)

        for myopt, kwargs in argument_options.iteritems():
                parser.add_option(myopt,
                        dest=myopt.lstrip("--").replace("-", "_"), **kwargs)

        tmpcmdline = insert_optional_args(tmpcmdline)

        myoptions, myargs = parser.parse_args(args=tmpcmdline)

        if myoptions.jobs:
                jobs = None
                if myoptions.jobs == "True":
                        jobs = True
                else:
                        try:
                                jobs = int(myoptions.jobs)
                        except ValueError:
                                jobs = -1

                if jobs is not True and \
                        jobs < 1:
                        jobs = None
                        if not silent:
                                writemsg("!!! Invalid --jobs parameter: '%s'\n" % \
                                        (myoptions.jobs,), noiselevel=-1)

                myoptions.jobs = jobs

        if myoptions.load_average:
                try:
                        load_average = float(myoptions.load_average)
                except ValueError:
                        load_average = 0.0

                if load_average <= 0.0:
                        load_average = None
                        if not silent:
                                writemsg("!!! Invalid --load-average parameter: '%s'\n" % \
                                        (myoptions.load_average,), noiselevel=-1)

                myoptions.load_average = load_average

        for myopt in options:
                v = getattr(myoptions, myopt.lstrip("--").replace("-", "_"))
                if v:
                        myopts[myopt] = True

        for myopt in argument_options:
                v = getattr(myoptions, myopt.lstrip("--").replace("-", "_"), None)
                if v is not None:
                        myopts[myopt] = v

        for action_opt in actions:
                v = getattr(myoptions, action_opt.replace("-", "_"))
                if v:
                        if myaction:
                                multiple_actions(myaction, action_opt)
                                sys.exit(1)
                        myaction = action_opt

        myfiles += myargs

        return myaction, myopts, myfiles

def validate_ebuild_environment(trees):
        for myroot in trees:
                settings = trees[myroot]["vartree"].settings
                settings.validate()

def clear_caches(trees):
        for d in trees.itervalues():
                d["porttree"].dbapi.melt()
                d["porttree"].dbapi._aux_cache.clear()
                d["bintree"].dbapi._aux_cache.clear()
                d["bintree"].dbapi._clear_cache()
                d["vartree"].dbapi.linkmap._clear_cache()
        portage.dircache.clear()
        gc.collect()

def load_emerge_config(trees=None):
        kwargs = {}
        for k, envvar in (("config_root", "PORTAGE_CONFIGROOT"), ("target_root", "ROOT")):
                v = os.environ.get(envvar, None)
                if v and v.strip():
                        kwargs[k] = v
        trees = portage.create_trees(trees=trees, **kwargs)

        for root, root_trees in trees.iteritems():
                settings = root_trees["vartree"].settings
                setconfig = load_default_config(settings, root_trees)
                root_trees["root_config"] = RootConfig(settings, root_trees, setconfig)

        settings = trees["/"]["vartree"].settings

        for myroot in trees:
                if myroot != "/":
                        settings = trees[myroot]["vartree"].settings
                        break

        mtimedbfile = os.path.join("/", portage.CACHE_PATH.lstrip(os.path.sep), "mtimedb")
        mtimedb = portage.MtimeDB(mtimedbfile)
        
        return settings, trees, mtimedb

def adjust_config(myopts, settings):
        """Make emerge specific adjustments to the config."""

        # To enhance usability, make some vars case insensitive by forcing them to
        # lower case.
        for myvar in ("AUTOCLEAN", "NOCOLOR"):
                if myvar in settings:
                        settings[myvar] = settings[myvar].lower()
                        settings.backup_changes(myvar)
        del myvar

        # Kill noauto as it will break merges otherwise.
        if "noauto" in settings.features:
                while "noauto" in settings.features:
                        settings.features.remove("noauto")
                settings["FEATURES"] = " ".join(settings.features)
                settings.backup_changes("FEATURES")

        CLEAN_DELAY = 5
        try:
                CLEAN_DELAY = int(settings.get("CLEAN_DELAY", str(CLEAN_DELAY)))
        except ValueError, e:
                portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
                portage.writemsg("!!! Unable to parse integer: CLEAN_DELAY='%s'\n" % \
                        settings["CLEAN_DELAY"], noiselevel=-1)
        settings["CLEAN_DELAY"] = str(CLEAN_DELAY)
        settings.backup_changes("CLEAN_DELAY")

        EMERGE_WARNING_DELAY = 10
        try:
                EMERGE_WARNING_DELAY = int(settings.get(
                        "EMERGE_WARNING_DELAY", str(EMERGE_WARNING_DELAY)))
        except ValueError, e:
                portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
                portage.writemsg("!!! Unable to parse integer: EMERGE_WARNING_DELAY='%s'\n" % \
                        settings["EMERGE_WARNING_DELAY"], noiselevel=-1)
        settings["EMERGE_WARNING_DELAY"] = str(EMERGE_WARNING_DELAY)
        settings.backup_changes("EMERGE_WARNING_DELAY")

        if "--quiet" in myopts:
                settings["PORTAGE_QUIET"]="1"
                settings.backup_changes("PORTAGE_QUIET")

        if "--verbose" in myopts:
                settings["PORTAGE_VERBOSE"] = "1"
                settings.backup_changes("PORTAGE_VERBOSE")

        # Set so that configs will be merged regardless of remembered status
        if ("--noconfmem" in myopts):
                settings["NOCONFMEM"]="1"
                settings.backup_changes("NOCONFMEM")

        # Set various debug markers... They should be merged somehow.
        PORTAGE_DEBUG = 0
        try:
                PORTAGE_DEBUG = int(settings.get("PORTAGE_DEBUG", str(PORTAGE_DEBUG)))
                if PORTAGE_DEBUG not in (0, 1):
                        portage.writemsg("!!! Invalid value: PORTAGE_DEBUG='%i'\n" % \
                                PORTAGE_DEBUG, noiselevel=-1)
                        portage.writemsg("!!! PORTAGE_DEBUG must be either 0 or 1\n",
                                noiselevel=-1)
                        PORTAGE_DEBUG = 0
        except ValueError, e:
                portage.writemsg("!!! %s\n" % str(e), noiselevel=-1)
                portage.writemsg("!!! Unable to parse integer: PORTAGE_DEBUG='%s'\n" %\
                        settings["PORTAGE_DEBUG"], noiselevel=-1)
                del e
        if "--debug" in myopts:
                PORTAGE_DEBUG = 1
        settings["PORTAGE_DEBUG"] = str(PORTAGE_DEBUG)
        settings.backup_changes("PORTAGE_DEBUG")

        if settings.get("NOCOLOR") not in ("yes","true"):
                portage.output.havecolor = 1

        """The explicit --color < y | n > option overrides the NOCOLOR environment
        variable and stdout auto-detection."""
        if "--color" in myopts:
                if "y" == myopts["--color"]:
                        portage.output.havecolor = 1
                        settings["NOCOLOR"] = "false"
                else:
                        portage.output.havecolor = 0
                        settings["NOCOLOR"] = "true"
                settings.backup_changes("NOCOLOR")
        elif not sys.stdout.isatty() and settings.get("NOCOLOR") != "no":
                portage.output.havecolor = 0
                settings["NOCOLOR"] = "true"
                settings.backup_changes("NOCOLOR")

def apply_priorities(settings):
        ionice(settings)
        nice(settings)

def nice(settings):
        try:
                os.nice(int(settings.get("PORTAGE_NICENESS", "0")))
        except (OSError, ValueError), e:
                out = portage.output.EOutput()
                out.eerror("Failed to change nice value to '%s'" % \
                        settings["PORTAGE_NICENESS"])
                out.eerror("%s\n" % str(e))

def ionice(settings):

        ionice_cmd = settings.get("PORTAGE_IONICE_COMMAND")
        if ionice_cmd:
                ionice_cmd = shlex.split(ionice_cmd)
        if not ionice_cmd:
                return

        from portage.util import varexpand
        variables = {"PID" : str(os.getpid())}
        cmd = [varexpand(x, mydict=variables) for x in ionice_cmd]

        try:
                rval = portage.process.spawn(cmd, env=os.environ)
        except portage.exception.CommandNotFound:
                # The OS kernel probably doesn't support ionice,
                # so return silently.
                return

        if rval != os.EX_OK:
                out = portage.output.EOutput()
                out.eerror("PORTAGE_IONICE_COMMAND returned %d" % (rval,))
                out.eerror("See the make.conf(5) man page for PORTAGE_IONICE_COMMAND usage instructions.")

def display_missing_pkg_set(root_config, set_name):

        msg = []
        msg.append(("emerge: There are no sets to satisfy '%s'. " + \
                "The following sets exist:") % \
                colorize("INFORM", set_name))
        msg.append("")

        for s in sorted(root_config.sets):
                msg.append("    %s" % s)
        msg.append("")

        writemsg_level("".join("%s\n" % l for l in msg),
                level=logging.ERROR, noiselevel=-1)

def expand_set_arguments(myfiles, myaction, root_config):
        retval = os.EX_OK
        setconfig = root_config.setconfig

        sets = setconfig.getSets()

        # In order to know exactly which atoms/sets should be added to the
        # world file, the depgraph performs set expansion later. It will get
        # confused about where the atoms came from if it's not allowed to
        # expand them itself.
        do_not_expand = (None, )
        newargs = []
        for a in myfiles:
                if a in ("system", "world"):
                        newargs.append(SETPREFIX+a)
                else:
                        newargs.append(a)
        myfiles = newargs
        del newargs
        newargs = []

        # separators for set arguments
        ARG_START = "{"
        ARG_END = "}"

        # WARNING: all operators must be of equal length
        IS_OPERATOR = "/@"
        DIFF_OPERATOR = "-@"
        UNION_OPERATOR = "+@"
        
        for i in range(0, len(myfiles)):
                if myfiles[i].startswith(SETPREFIX):
                        start = 0
                        end = 0
                        x = myfiles[i][len(SETPREFIX):]
                        newset = ""
                        while x:
                                start = x.find(ARG_START)
                                end = x.find(ARG_END)
                                if start > 0 and start < end:
                                        namepart = x[:start]
                                        argpart = x[start+1:end]
                                
                                        # TODO: implement proper quoting
                                        args = argpart.split(",")
                                        options = {}
                                        for a in args:
                                                if "=" in a:
                                                        k, v  = a.split("=", 1)
                                                        options[k] = v
                                                else:
                                                        options[a] = "True"
                                        setconfig.update(namepart, options)
                                        newset += (x[:start-len(namepart)]+namepart)
                                        x = x[end+len(ARG_END):]
                                else:
                                        newset += x
                                        x = ""
                        myfiles[i] = SETPREFIX+newset
                                
        sets = setconfig.getSets()

        # display errors that occured while loading the SetConfig instance
        for e in setconfig.errors:
                print colorize("BAD", "Error during set creation: %s" % e)
        
        # emerge relies on the existance of sets with names "world" and "system"
        required_sets = ("world", "system")

        for s in required_sets:
                if s not in sets:
                        msg = ["emerge: incomplete set configuration, " + \
                                "no \"%s\" set defined" % s]
                        msg.append("        sets defined: %s" % ", ".join(sets))
                        for line in msg:
                                sys.stderr.write(line + "\n")
                        retval = 1
        unmerge_actions = ("unmerge", "prune", "clean", "depclean")

        for a in myfiles:
                if a.startswith(SETPREFIX):
                        # support simple set operations (intersection, difference and union)
                        # on the commandline. Expressions are evaluated strictly left-to-right
                        if IS_OPERATOR in a or DIFF_OPERATOR in a or UNION_OPERATOR in a:
                                expression = a[len(SETPREFIX):]
                                expr_sets = []
                                expr_ops = []
                                while IS_OPERATOR in expression or DIFF_OPERATOR in expression or UNION_OPERATOR in expression:
                                        is_pos = expression.rfind(IS_OPERATOR)
                                        diff_pos = expression.rfind(DIFF_OPERATOR)
                                        union_pos = expression.rfind(UNION_OPERATOR)
                                        op_pos = max(is_pos, diff_pos, union_pos)
                                        s1 = expression[:op_pos]
                                        s2 = expression[op_pos+len(IS_OPERATOR):]
                                        op = expression[op_pos:op_pos+len(IS_OPERATOR)]
                                        if not s2 in sets:
                                                display_missing_pkg_set(root_config, s2)
                                                return (None, 1)
                                        expr_sets.insert(0, s2)
                                        expr_ops.insert(0, op)
                                        expression = s1
                                if not expression in sets:
                                        display_missing_pkg_set(root_config, expression)
                                        return (None, 1)
                                expr_sets.insert(0, expression)
                                result = set(setconfig.getSetAtoms(expression))
                                for i in range(0, len(expr_ops)):
                                        s2 = setconfig.getSetAtoms(expr_sets[i+1])
                                        if expr_ops[i] == IS_OPERATOR:
                                                result.intersection_update(s2)
                                        elif expr_ops[i] == DIFF_OPERATOR:
                                                result.difference_update(s2)
                                        elif expr_ops[i] == UNION_OPERATOR:
                                                result.update(s2)
                                        else:
                                                raise NotImplementedError("unknown set operator %s" % expr_ops[i])
                                newargs.extend(result)
                        else:                   
                                s = a[len(SETPREFIX):]
                                if s not in sets:
                                        display_missing_pkg_set(root_config, s)
                                        return (None, 1)
                                setconfig.active.append(s)
                                try:
                                        set_atoms = setconfig.getSetAtoms(s)
                                except portage.exception.PackageSetNotFound, e:
                                        writemsg_level(("emerge: the given set '%s' " + \
                                                "contains a non-existent set named '%s'.\n") % \
                                                (s, e), level=logging.ERROR, noiselevel=-1)
                                        return (None, 1)
                                if myaction in unmerge_actions and \
                                                not sets[s].supportsOperation("unmerge"):
                                        sys.stderr.write("emerge: the given set '%s' does " % s + \
                                                "not support unmerge operations\n")
                                        retval = 1
                                elif not set_atoms:
                                        print "emerge: '%s' is an empty set" % s
                                elif myaction not in do_not_expand:
                                        newargs.extend(set_atoms)
                                else:
                                        newargs.append(SETPREFIX+s)
                                for e in sets[s].errors:
                                        print e
                else:
                        newargs.append(a)
        return (newargs, retval)

def repo_name_check(trees):
        missing_repo_names = set()
        for root, root_trees in trees.iteritems():
                if "porttree" in root_trees:
                        portdb = root_trees["porttree"].dbapi
                        missing_repo_names.update(portdb.porttrees)
                        repos = portdb.getRepositories()
                        for r in repos:
                                missing_repo_names.discard(portdb.getRepositoryPath(r))

        if missing_repo_names:
                msg = []
                msg.append("WARNING: One or more repositories " + \
                        "have missing repo_name entries:")
                msg.append("")
                for p in missing_repo_names:
                        msg.append("\t%s/profiles/repo_name" % (p,))
                msg.append("")
                msg.extend(textwrap.wrap("NOTE: Each repo_name entry " + \
                        "should be a plain text file containing a unique " + \
                        "name for the repository on the first line.", 70))
                writemsg_level("".join("%s\n" % l for l in msg),
                        level=logging.WARNING, noiselevel=-1)

        return bool(missing_repo_names)

def config_protect_check(trees):
        for root, root_trees in trees.iteritems():
                if not root_trees["root_config"].settings.get("CONFIG_PROTECT"):
                        msg = "!!! CONFIG_PROTECT is empty"
                        if root != "/":
                                msg += " for '%s'" % root
                        writemsg_level(msg, level=logging.WARN, noiselevel=-1)

def ambiguous_package_name(arg, atoms, root_config, spinner, myopts):

        if "--quiet" in myopts:
                print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
                print "!!! one of the following fully-qualified ebuild names instead:\n"
                for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
                        print "    " + colorize("INFORM", cp)
                return

        s = search(root_config, spinner, "--searchdesc" in myopts,
                "--quiet" not in myopts, "--usepkg" in myopts,
                "--usepkgonly" in myopts)
        null_cp = portage.dep_getkey(insert_category_into_atom(
                arg, "null"))
        cat, atom_pn = portage.catsplit(null_cp)
        s.searchkey = atom_pn
        for cp in sorted(set(portage.dep_getkey(atom) for atom in atoms)):
                s.addCP(cp)
        s.output()
        print "!!! The short ebuild name \"%s\" is ambiguous. Please specify" % arg
        print "!!! one of the above fully-qualified ebuild names instead.\n"

def profile_check(trees, myaction, myopts):
        if myaction in ("info", "sync"):
                return os.EX_OK
        elif "--version" in myopts or "--help" in myopts:
                return os.EX_OK
        for root, root_trees in trees.iteritems():
                if root_trees["root_config"].settings.profiles:
                        continue
                # generate some profile related warning messages
                validate_ebuild_environment(trees)
                msg = "If you have just changed your profile configuration, you " + \
                        "should revert back to the previous configuration. Due to " + \
                        "your current profile being invalid, allowed actions are " + \
                        "limited to --help, --info, --sync, and --version."
                writemsg_level("".join("!!! %s\n" % l for l in textwrap.wrap(msg, 70)),
                        level=logging.ERROR, noiselevel=-1)
                return 1
        return os.EX_OK

def emerge_main():
        global portage  # NFC why this is necessary now - genone
        portage._disable_legacy_globals()
        # Disable color until we're sure that it should be enabled (after
        # EMERGE_DEFAULT_OPTS has been parsed).
        portage.output.havecolor = 0
        # This first pass is just for options that need to be known as early as
        # possible, such as --config-root.  They will be parsed again later,
        # together with EMERGE_DEFAULT_OPTS (which may vary depending on the
        # the value of --config-root).
        myaction, myopts, myfiles = parse_opts(sys.argv[1:], silent=True)
        if "--debug" in myopts:
                os.environ["PORTAGE_DEBUG"] = "1"
        if "--config-root" in myopts:
                os.environ["PORTAGE_CONFIGROOT"] = myopts["--config-root"]

        # Portage needs to ensure a sane umask for the files it creates.
        os.umask(022)
        settings, trees, mtimedb = load_emerge_config()
        portdb = trees[settings["ROOT"]]["porttree"].dbapi
        rval = profile_check(trees, myaction, myopts)
        if rval != os.EX_OK:
                return rval

        if portage._global_updates(trees, mtimedb["updates"]):
                mtimedb.commit()
                # Reload the whole config from scratch.
                settings, trees, mtimedb = load_emerge_config(trees=trees)
                portdb = trees[settings["ROOT"]]["porttree"].dbapi

        xterm_titles = "notitles" not in settings.features

        tmpcmdline = []
        if "--ignore-default-opts" not in myopts:
                tmpcmdline.extend(settings["EMERGE_DEFAULT_OPTS"].split())
        tmpcmdline.extend(sys.argv[1:])
        myaction, myopts, myfiles = parse_opts(tmpcmdline)

        if "--digest" in myopts:
                os.environ["FEATURES"] = os.environ.get("FEATURES","") + " digest"
                # Reload the whole config from scratch so that the portdbapi internal
                # config is updated with new FEATURES.
                settings, trees, mtimedb = load_emerge_config(trees=trees)
                portdb = trees[settings["ROOT"]]["porttree"].dbapi

        for myroot in trees:
                mysettings =  trees[myroot]["vartree"].settings
                mysettings.unlock()
                adjust_config(myopts, mysettings)
                mysettings["PORTAGE_COUNTER_HASH"] = \
                        trees[myroot]["vartree"].dbapi._counter_hash()
                mysettings.backup_changes("PORTAGE_COUNTER_HASH")
                mysettings.lock()
                del myroot, mysettings

        apply_priorities(settings)

        spinner = stdout_spinner()
        if "candy" in settings.features:
                spinner.update = spinner.update_scroll

        if "--quiet" not in myopts:
                portage.deprecated_profile_check()
                repo_name_check(trees)
                config_protect_check(trees)

        eclasses_overridden = {}
        for mytrees in trees.itervalues():
                mydb = mytrees["porttree"].dbapi
                # Freeze the portdbapi for performance (memoize all xmatch results).
                mydb.freeze()
                eclasses_overridden.update(mydb.eclassdb._master_eclasses_overridden)
        del mytrees, mydb

        if eclasses_overridden and \
                settings.get("PORTAGE_ECLASS_WARNING_ENABLE") != "0":
                prefix = bad(" * ")
                if len(eclasses_overridden) == 1:
                        writemsg(prefix + "Overlay eclass overrides " + \
                                "eclass from PORTDIR:\n", noiselevel=-1)
                else:
                        writemsg(prefix + "Overlay eclasses override " + \
                                "eclasses from PORTDIR:\n", noiselevel=-1)
                writemsg(prefix + "\n", noiselevel=-1)
                for eclass_name in sorted(eclasses_overridden):
                        writemsg(prefix + "  '%s/%s.eclass'\n" % \
                                (eclasses_overridden[eclass_name], eclass_name),
                                noiselevel=-1)
                writemsg(prefix + "\n", noiselevel=-1)
                msg = "It is best to avoid overriding eclasses from PORTDIR " + \
                "because it will trigger invalidation of cached ebuild metadata " + \
                "that is distributed with the portage tree. If you must " + \
                "override eclasses from PORTDIR then you are advised to add " + \
                "FEATURES=\"metadata-transfer\" to /etc/make.conf and to run " + \
                "`emerge --regen` after each time that you run `emerge --sync`. " + \
                "Set PORTAGE_ECLASS_WARNING_ENABLE=\"0\" in /etc/make.conf if " + \
                "you would like to disable this warning."
                from textwrap import wrap
                for line in wrap(msg, 72):
                        writemsg("%s%s\n" % (prefix, line), noiselevel=-1)

        if "moo" in myfiles:
                print """

  Larry loves Gentoo (""" + platform.system() + """)

 _______________________
< Have you mooed today? >
 -----------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\ 
                ||----w |
                ||     ||

"""

        for x in myfiles:
                ext = os.path.splitext(x)[1]
                if (ext == ".ebuild" or ext == ".tbz2") and os.path.exists(os.path.abspath(x)):
                        print colorize("BAD", "\n*** emerging by path is broken and may not always work!!!\n")
                        break

        root_config = trees[settings["ROOT"]]["root_config"]
        if myaction == "list-sets":
                sys.stdout.write("".join("%s\n" % s for s in sorted(root_config.sets)))
                sys.stdout.flush()
                return os.EX_OK

        # only expand sets for actions taking package arguments
        oldargs = myfiles[:]
        if myaction in ("clean", "config", "depclean", "info", "prune", "unmerge", None):
                myfiles, retval = expand_set_arguments(myfiles, myaction, root_config)
                if retval != os.EX_OK:
                        return retval

                # Need to handle empty sets specially, otherwise emerge will react 
                # with the help message for empty argument lists
                if oldargs and not myfiles:
                        print "emerge: no targets left after set expansion"
                        return 0

        if ("--tree" in myopts) and ("--columns" in myopts):
                print "emerge: can't specify both of \"--tree\" and \"--columns\"."
                return 1

        if ("--quiet" in myopts):
                spinner.update = spinner.update_quiet
                portage.util.noiselimit = -1

        # Always create packages if FEATURES=buildpkg
        # Imply --buildpkg if --buildpkgonly
        if ("buildpkg" in settings.features) or ("--buildpkgonly" in myopts):
                if "--buildpkg" not in myopts:
                        myopts["--buildpkg"] = True

        # Also allow -S to invoke search action (-sS)
        if ("--searchdesc" in myopts):
                if myaction and myaction != "search":
                        myfiles.append(myaction)
                if "--search" not in myopts:
                        myopts["--search"] = True
                myaction = "search"

        # Always try and fetch binary packages if FEATURES=getbinpkg
        if ("getbinpkg" in settings.features):
                myopts["--getbinpkg"] = True

        if "--buildpkgonly" in myopts:
                # --buildpkgonly will not merge anything, so
                # it cancels all binary package options.
                for opt in ("--getbinpkg", "--getbinpkgonly",
                        "--usepkg", "--usepkgonly"):
                        myopts.pop(opt, None)

        if "--fetch-all-uri" in myopts:
                myopts["--fetchonly"] = True

        if "--skipfirst" in myopts and "--resume" not in myopts:
                myopts["--resume"] = True

        if ("--getbinpkgonly" in myopts) and not ("--usepkgonly" in myopts):
                myopts["--usepkgonly"] = True

        if ("--getbinpkgonly" in myopts) and not ("--getbinpkg" in myopts):
                myopts["--getbinpkg"] = True

        if ("--getbinpkg" in myopts) and not ("--usepkg" in myopts):
                myopts["--usepkg"] = True

        # Also allow -K to apply --usepkg/-k
        if ("--usepkgonly" in myopts) and not ("--usepkg" in myopts):
                myopts["--usepkg"] = True

        # Allow -p to remove --ask
        if ("--pretend" in myopts) and ("--ask" in myopts):
                print ">>> --pretend disables --ask... removing --ask from options."
                del myopts["--ask"]

        # forbid --ask when not in a terminal
        # note: this breaks `emerge --ask | tee logfile`, but that doesn't work anyway.
        if ("--ask" in myopts) and (not sys.stdin.isatty()):
                portage.writemsg("!!! \"--ask\" should only be used in a terminal. Exiting.\n",
                        noiselevel=-1)
                return 1

        if settings.get("PORTAGE_DEBUG", "") == "1":
                spinner.update = spinner.update_quiet
                portage.debug=1
                if "python-trace" in settings.features:
                        import portage.debug
                        portage.debug.set_trace(True)

        if not ("--quiet" in myopts):
                if not sys.stdout.isatty() or ("--nospinner" in myopts):
                        spinner.update = spinner.update_basic

        if "--version" in myopts:
                print getportageversion(settings["PORTDIR"], settings["ROOT"],
                        settings.profile_path, settings["CHOST"],
                        trees[settings["ROOT"]]["vartree"].dbapi)
                return 0
        elif "--help" in myopts:
                _emerge.help.help(myaction, myopts, portage.output.havecolor)
                return 0

        if "--debug" in myopts:
                print "myaction", myaction
                print "myopts", myopts

        if not myaction and not myfiles and "--resume" not in myopts:
                _emerge.help.help(myaction, myopts, portage.output.havecolor)
                return 1

        pretend = "--pretend" in myopts
        fetchonly = "--fetchonly" in myopts or "--fetch-all-uri" in myopts
        buildpkgonly = "--buildpkgonly" in myopts

        # check if root user is the current user for the actions where emerge needs this
        if portage.secpass < 2:
                # We've already allowed "--version" and "--help" above.
                if "--pretend" not in myopts and myaction not in ("search","info"):
                        need_superuser = not \
                                (fetchonly or \
                                (buildpkgonly and secpass >= 1) or \
                                myaction in ("metadata", "regen") or \
                                (myaction == "sync" and os.access(settings["PORTDIR"], os.W_OK)))
                        if portage.secpass < 1 or \
                                need_superuser:
                                if need_superuser:
                                        access_desc = "superuser"
                                else:
                                        access_desc = "portage group"
                                # Always show portage_group_warning() when only portage group
                                # access is required but the user is not in the portage group.
                                from portage.data import portage_group_warning
                                if "--ask" in myopts:
                                        myopts["--pretend"] = True
                                        del myopts["--ask"]
                                        print ("%s access is required... " + \
                                                "adding --pretend to options.\n") % access_desc
                                        if portage.secpass < 1 and not need_superuser:
                                                portage_group_warning()
                                else:
                                        sys.stderr.write(("emerge: %s access is " + \
                                                "required.\n\n") % access_desc)
                                        if portage.secpass < 1 and not need_superuser:
                                                portage_group_warning()
                                        return 1

        disable_emergelog = False
        for x in ("--pretend", "--fetchonly", "--fetch-all-uri"):
                if x in myopts:
                        disable_emergelog = True
                        break
        if myaction in ("search", "info"):
                disable_emergelog = True
        if disable_emergelog:
                """ Disable emergelog for everything except build or unmerge
                operations.  This helps minimize parallel emerge.log entries that can
                confuse log parsers.  We especially want it disabled during
                parallel-fetch, which uses --resume --fetchonly."""
                global emergelog
                def emergelog(*pargs, **kargs):
                        pass

        if not "--pretend" in myopts:
                emergelog(xterm_titles, "Started emerge on: "+\
                        time.strftime("%b %d, %Y %H:%M:%S", time.localtime()))
                myelogstr=""
                if myopts:
                        myelogstr=" ".join(myopts)
                if myaction:
                        myelogstr+=" "+myaction
                if myfiles:
                        myelogstr += " " + " ".join(oldargs)
                emergelog(xterm_titles, " *** emerge " + myelogstr)
        del oldargs

        def emergeexitsig(signum, frame):
                signal.signal(signal.SIGINT, signal.SIG_IGN)
                signal.signal(signal.SIGTERM, signal.SIG_IGN)
                portage.util.writemsg("\n\nExiting on signal %(signal)s\n" % {"signal":signum})
                sys.exit(100+signum)
        signal.signal(signal.SIGINT, emergeexitsig)
        signal.signal(signal.SIGTERM, emergeexitsig)

        def emergeexit():
                """This gets out final log message in before we quit."""
                if "--pretend" not in myopts:
                        emergelog(xterm_titles, " *** terminating.")
                if "notitles" not in settings.features:
                        xtermTitleReset()
        portage.atexit_register(emergeexit)

        if myaction in ("config", "metadata", "regen", "sync"):
                if "--pretend" in myopts:
                        sys.stderr.write(("emerge: The '%s' action does " + \
                                "not support '--pretend'.\n") % myaction)
                        return 1

        if "sync" == myaction:
                return action_sync(settings, trees, mtimedb, myopts, myaction)
        elif "metadata" == myaction:
                action_metadata(settings, portdb, myopts)
        elif myaction=="regen":
                validate_ebuild_environment(trees)
                action_regen(settings, portdb, myopts.get("--jobs"),
                        myopts.get("--load-average"))
        # HELP action
        elif "config"==myaction:
                validate_ebuild_environment(trees)
                action_config(settings, trees, myopts, myfiles)

        # SEARCH action
        elif "search"==myaction:
                validate_ebuild_environment(trees)
                action_search(trees[settings["ROOT"]]["root_config"],
                        myopts, myfiles, spinner)
        elif myaction in ("clean", "unmerge") or \
                (myaction == "prune" and "--nodeps" in myopts):
                validate_ebuild_environment(trees)

                # Ensure atoms are valid before calling unmerge().
                # For backward compat, leading '=' is not required.
                for x in myfiles:
                        if is_valid_package_atom(x) or \
                                is_valid_package_atom("=" + x):
                                continue
                        msg = []
                        msg.append("'%s' is not a valid package atom." % (x,))
                        msg.append("Please check ebuild(5) for full details.")
                        writemsg_level("".join("!!! %s\n" % line for line in msg),
                                level=logging.ERROR, noiselevel=-1)
                        return 1

                # When given a list of atoms, unmerge
                # them in the order given.
                ordered = myaction == "unmerge"
                if 1 == unmerge(root_config, myopts, myaction, myfiles,
                        mtimedb["ldpath"], ordered=ordered):
                        if not (buildpkgonly or fetchonly or pretend):
                                post_emerge(root_config, myopts, mtimedb, os.EX_OK)

        elif myaction in ("depclean", "info", "prune"):

                # Ensure atoms are valid before calling unmerge().
                vardb = trees[settings["ROOT"]]["vartree"].dbapi
                valid_atoms = []
                for x in myfiles:
                        if is_valid_package_atom(x):
                                try:
                                        valid_atoms.append(
                                                portage.dep_expand(x, mydb=vardb, settings=settings))
                                except portage.exception.AmbiguousPackageName, e:
                                        msg = "The short ebuild name \"" + x + \
                                                "\" is ambiguous.  Please specify " + \
                                                "one of the following " + \
                                                "fully-qualified ebuild names instead:"
                                        for line in textwrap.wrap(msg, 70):
                                                writemsg_level("!!! %s\n" % (line,),
                                                        level=logging.ERROR, noiselevel=-1)
                                        for i in e[0]:
                                                writemsg_level("    %s\n" % colorize("INFORM", i),
                                                        level=logging.ERROR, noiselevel=-1)
                                        writemsg_level("\n", level=logging.ERROR, noiselevel=-1)
                                        return 1
                                continue
                        msg = []
                        msg.append("'%s' is not a valid package atom." % (x,))
                        msg.append("Please check ebuild(5) for full details.")
                        writemsg_level("".join("!!! %s\n" % line for line in msg),
                                level=logging.ERROR, noiselevel=-1)
                        return 1

                if myaction == "info":
                        return action_info(settings, trees, myopts, valid_atoms)

                validate_ebuild_environment(trees)
                action_depclean(settings, trees, mtimedb["ldpath"],
                        myopts, myaction, valid_atoms, spinner)
                if not (buildpkgonly or fetchonly or pretend):
                        post_emerge(root_config, myopts, mtimedb, os.EX_OK)
        # "update", "system", or just process files:
        else:
                validate_ebuild_environment(trees)
                if "--pretend" not in myopts:
                        display_news_notification(root_config, myopts)
                retval = action_build(settings, trees, mtimedb,
                        myopts, myaction, myfiles, spinner)
                root_config = trees[settings["ROOT"]]["root_config"]
                post_emerge(root_config, myopts, mtimedb, retval)

                return retval