REQUIRED_USE: always show requirements

This fixes a case in which the user would receive a "masked by:
REQUIRED_USE violated" message without any more information about
the specific requirements. Now, unsatisfied REQUIRED_USE is never
treated as a mask, since it really is nothing like a mask. It's much
more like an unsatisfied USE dependency, so we need to handle it in
a similar way.

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 8ea9c8bbf540d123d50a3b7cfcb026e97b928da6..ebfefc727ed5237325852b2df1e2794e4eeb6bd4 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -2207,6 +2207,8 @@ class depgraph(object):
                        xinfo = "%s for %s" % (xinfo, root)
                masked_packages = []
                missing_use = []
+               missing_use_adjustable = set()
+               required_use_unsatisfied = []
                masked_pkg_instances = set()
                missing_licenses = []
                have_eapi_mask = False
@@ -2264,6 +2266,16 @@ class depgraph(object):
                                                                "InvalidAtom: '%s' parent: %s" % \
                                                                (atom, myparent), noiselevel=-1)
                                                        raise
+                                       if not mreasons and \
+                                               not pkg.built and \
+                                               pkg.metadata["REQUIRED_USE"] and \
+                                               eapi_has_required_use(pkg.metadata["EAPI"]):
+                                               if not check_required_use(
+                                                       pkg.metadata["REQUIRED_USE"],
+                                                       self._pkg_use_enabled(pkg),
+                                                       pkg.iuse.is_valid_flag):
+                                                       required_use_unsatisfied.append(pkg)
+                                               continue
                                        if pkg.built and not mreasons:
                                                mreasons = ["use flag configuration mismatch"]
                                masked_packages.append(
@@ -2299,6 +2311,7 @@ class depgraph(object):
                                        chain(need_enable, need_disable)):
                                        continue
 
+                               missing_use_adjustable.add(pkg)
                                required_use = pkg.metadata["REQUIRED_USE"]
                                required_use_warning = ""
                                if required_use:
@@ -2412,9 +2425,38 @@ class depgraph(object):
                        if not masked_with_iuse:
                                show_missing_use = unmasked_iuse_reasons
 
+               if required_use_unsatisfied:
+                       # If there's a higher unmasked version in missing_use_adjustable
+                       # then we want to show that instead.
+                       for pkg in missing_use_adjustable:
+                               if pkg not in masked_pkg_instances and \
+                                       pkg > required_use_unsatisfied[0]:
+                                       required_use_unsatisfied = False
+                                       break
+
                mask_docs = False
 
-               if show_missing_use:
+               if required_use_unsatisfied:
+                       # We have an unmasked package that only requires USE adjustment
+                       # in order to satisfy REQUIRED_USE, and nothing more. We assume
+                       # that the user wants the latest version, so only the first
+                       # instance is displayed.
+                       pkg = required_use_unsatisfied[0]
+                       output_cpv = pkg.cpv
+                       writemsg_stdout("\n!!! " + \
+                               colorize("BAD", "The ebuild selected to satisfy ") + \
+                               colorize("INFORM", xinfo) + \
+                               colorize("BAD", " has unmet requirements.") + "\n",
+                               noiselevel=-1)
+                       writemsg_stdout("- %s (REQUIRED_USE unsatisifed)\n" % \
+                               (output_cpv,), noiselevel=-1)
+                       writemsg_stdout("\n  The following use flag constraints " + \
+                               "are unsatisfied:\n", noiselevel=-1)
+                       writemsg_stdout("    %s\n" % \
+                               human_readable_required_use(pkg.metadata["REQUIRED_USE"]),
+                               noiselevel=-1)
+
+               elif show_missing_use:
                        writemsg_stdout("\nemerge: there are no ebuilds built with USE flags to satisfy "+green(xinfo)+".\n", noiselevel=-1)
                        writemsg_stdout("!!! One of the following packages is required to complete your request:\n", noiselevel=-1)
                        for pkg, mreasons in show_missing_use:
@@ -5745,21 +5787,6 @@ def _get_masking_status(pkg, pkgsettings, root_config, use=None):
                        mreasons.append(_MaskReason("CHOST", "CHOST: %s" % \
                                pkg.metadata["CHOST"]))
 
-               if pkg.metadata["REQUIRED_USE"] and \
-                       eapi_has_required_use(pkg.metadata["EAPI"]):
-                       required_use = pkg.metadata["REQUIRED_USE"]
-                       if use is None:
-                               use = pkg.use.enabled
-                       try:
-                               required_use_is_sat = check_required_use(
-                                       required_use, use, pkg.iuse.is_valid_flag)
-                       except portage.exception.InvalidDependString:
-                               mreasons.append(_MaskReason("invalid", "invalid: REQUIRED_USE"))
-                       else:
-                               if not required_use_is_sat:
-                                       msg = "violated use flag constraints: '%s'" % required_use
-                                       mreasons.append(_MaskReason("REQUIRED_USE", "REQUIRED_USE violated"))
-
        if pkg.invalid:
                for msg_type, msgs in pkg.invalid.items():
                        for msg in msgs: