resume_depgraph: check for alternative installed

When pruning packages from the merge list, only prune them if the
relevant dependency is not satisfied by an alternative package which
is already installed. This should fix bug #448176, and now there's also
reasons logged for why a particular package is dropped.

diff --git a/pym/_emerge/Scheduler.py b/pym/_emerge/Scheduler.py
index 6a494970e7b80b92e3a33a1fbe832b71501fba8d..a4232747371628e3c7ff273bb45a7093bd478748 100644 (file)
--- a/pym/_emerge/Scheduler.py
+++ b/pym/_emerge/Scheduler.py
@@ -1791,7 +1791,7 @@ class Scheduler(PollScheduler):
                        #              scope
                        e = exc
                        mydepgraph = e.depgraph
-                       dropped_tasks = set()
+                       dropped_tasks = {}
 
                if e is not None:
                        def unsatisfied_resume_dep_msg():
@@ -1841,7 +1841,7 @@ class Scheduler(PollScheduler):
                self._init_graph(mydepgraph.schedulerGraph())
 
                msg_width = 75
-               for task in dropped_tasks:
+               for task, atoms in dropped_tasks.items():
                        if not (isinstance(task, Package) and task.operation == "merge"):
                                continue
                        pkg = task
@@ -1849,7 +1849,10 @@ class Scheduler(PollScheduler):
                                " %s" % (pkg.cpv,)
                        if pkg.root_config.settings["ROOT"] != "/":
                                msg += " for %s" % (pkg.root,)
-                       msg += " dropped due to unsatisfied dependency."
+                       if not atoms:
+                               msg += " dropped because it is masked or unavailable"
+                       else:
+                               msg += " dropped because it requires %s" % ", ".join(atoms)
                        for line in textwrap.wrap(msg, msg_width):
                                eerror(line, phase="other", key=pkg.cpv)
                        settings = self.pkgsettings[pkg.root]

diff --git a/pym/_emerge/actions.py b/pym/_emerge/actions.py
index 6a3815a9cc6cca27f0aa5dd64c4b63a01f5991c1..19265d03e8477eb043e8852949a0348ccbda5ccb 100644 (file)
--- a/pym/_emerge/actions.py
+++ b/pym/_emerge/actions.py
@@ -286,8 +286,14 @@ def action_build(settings, trees, mtimedb,
                                        "dropped due to\n" + \
                                        "!!! masking or unsatisfied dependencies:\n\n",
                                        noiselevel=-1)
-                               for task in dropped_tasks:
-                                       portage.writemsg("  " + str(task) + "\n", noiselevel=-1)
+                               for task, atoms in dropped_tasks.items():
+                                       if not atoms:
+                                               writemsg("  %s is masked or unavailable\n" %
+                                                       (task,), noiselevel=-1)
+                                       else:
+                                               writemsg("  %s requires %s\n" %
+                                                       (task, ", ".join(atoms)), noiselevel=-1)
+
                                portage.writemsg("\n", noiselevel=-1)
                        del dropped_tasks
                else:

diff --git a/pym/_emerge/depgraph.py b/pym/_emerge/depgraph.py
index 47f1b6002f4e5289113c422467750a3e97d94f28..f02ccb6e9f423b8c52664a05db2c281c5e6a4f49 100644 (file)
--- a/pym/_emerge/depgraph.py
+++ b/pym/_emerge/depgraph.py
@@ -7477,7 +7477,7 @@ def _resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
        skip_masked = True
        skip_unsatisfied = True
        mergelist = mtimedb["resume"]["mergelist"]
-       dropped_tasks = set()
+       dropped_tasks = {}
        frozen_config = _frozen_depgraph_config(settings, trees,
                myopts, spinner)
        while True:
@@ -7491,12 +7491,21 @@ def _resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
                                raise
 
                        graph = mydepgraph._dynamic_config.digraph
-                       unsatisfied_parents = dict((dep.parent, dep.parent) \
-                               for dep in e.value)
+                       unsatisfied_parents = {}
                        traversed_nodes = set()
-                       unsatisfied_stack = list(unsatisfied_parents)
+                       unsatisfied_stack = [(dep.parent, dep.atom) for dep in e.value]
                        while unsatisfied_stack:
-                               pkg = unsatisfied_stack.pop()
+                               pkg, atom = unsatisfied_stack.pop()
+                               if atom is not None and \
+                                       mydepgraph._select_pkg_from_installed(
+                                       pkg.root, atom)[0] is not None:
+                                       continue
+                               atoms = unsatisfied_parents.get(pkg)
+                               if atoms is None:
+                                       atoms = []
+                                       unsatisfied_parents[pkg] = atoms
+                               if atom is not None:
+                                       atoms.append(atom)
                                if pkg in traversed_nodes:
                                        continue
                                traversed_nodes.add(pkg)
@@ -7505,7 +7514,8 @@ def _resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
                                # 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):
+                               for parent_node, atom in \
+                                       mydepgraph._dynamic_config._parent_atoms.get(pkg, []):
                                        if not isinstance(parent_node, Package) \
                                                or parent_node.operation not in ("merge", "nomerge"):
                                                continue
@@ -7513,8 +7523,7 @@ def _resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
                                        # ensure that a package with an unsatisfied depenedency
                                        # won't get pulled in, even indirectly via a soft
                                        # dependency.
-                                       unsatisfied_parents[parent_node] = parent_node
-                                       unsatisfied_stack.append(parent_node)
+                                       unsatisfied_stack.append((parent_node, atom))
 
                        unsatisfied_tuples = frozenset(tuple(parent_node)
                                for parent_node in unsatisfied_parents
@@ -7535,8 +7544,8 @@ def _resume_depgraph(settings, trees, mtimedb, myopts, myparams, spinner):
                        # 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")
+                       dropped_tasks.update((pkg, atoms) for pkg, atoms in \
+                               unsatisfied_parents.items() if pkg.operation != "nomerge")
 
                        del e, graph, traversed_nodes, \
                                unsatisfied_parents, unsatisfied_stack