lib/_emerge/actions.py

# Copyright 1999-2018 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

from __future__ import division, print_function, unicode_literals

import errno
import logging
import operator
import platform
import pwd
import random
import re
import signal
import socket
import stat
import subprocess
import sys
import tempfile
import textwrap
import time
import warnings
from itertools import chain

import portage
portage.proxy.lazyimport.lazyimport(globals(),
	'portage.dbapi._similar_name_search:similar_name_search',
	'portage.debug',
	'portage.news:count_unread_news,display_news_notifications',
	'portage.util._get_vm_info:get_vm_info',
	'portage.util.locale:check_locale',
	'portage.emaint.modules.sync.sync:SyncRepos',
	'_emerge.chk_updated_cfg_files:chk_updated_cfg_files',
	'_emerge.help:help@emerge_help',
	'_emerge.post_emerge:display_news_notification,post_emerge',
	'_emerge.stdout_spinner:stdout_spinner',
)

from portage import os
from portage import shutil
from portage import eapi_is_supported, _encodings, _unicode_decode
from portage.cache.cache_errors import CacheError
from portage.const import GLOBAL_CONFIG_PATH, VCS_DIRS, _DEPCLEAN_LIB_CHECK_DEFAULT
from portage.const import SUPPORTED_BINPKG_FORMATS, TIMESTAMP_FORMAT
from portage.dbapi.dep_expand import dep_expand
from portage.dbapi._expand_new_virt import expand_new_virt
from portage.dbapi.IndexedPortdb import IndexedPortdb
from portage.dbapi.IndexedVardb import IndexedVardb
from portage.dep import Atom, _repo_separator, _slot_separator
from portage.eclass_cache import hashed_path
from portage.exception import InvalidAtom, InvalidData, ParseError
from portage.output import blue, colorize, create_color_func, darkgreen, \
	red, xtermTitle, xtermTitleReset, yellow
good = create_color_func("GOOD")
bad = create_color_func("BAD")
warn = create_color_func("WARN")
from portage.package.ebuild._ipc.QueryCommand import QueryCommand
from portage.package.ebuild.doebuild import _check_temp_dir
from portage._sets import load_default_config, SETPREFIX
from portage._sets.base import InternalPackageSet
from portage.util import cmp_sort_key, writemsg, varexpand, \
	writemsg_level, writemsg_stdout
from portage.util.digraph import digraph
from portage.util.SlotObject import SlotObject
from portage.util._async.run_main_scheduler import run_main_scheduler
from portage.util._async.SchedulerInterface import SchedulerInterface
from portage.util._eventloop.global_event_loop import global_event_loop
from portage._global_updates import _global_updates
from portage.sync.old_tree_timestamp import old_tree_timestamp_warn
from portage.localization import _
from portage.metadata import action_metadata
from portage.emaint.main import print_results

from _emerge.clear_caches import clear_caches
from _emerge.countdown import countdown
from _emerge.create_depgraph_params import create_depgraph_params
from _emerge.Dependency import Dependency
from _emerge.depgraph import backtrack_depgraph, depgraph, resume_depgraph
from _emerge.DepPrioritySatisfiedRange import DepPrioritySatisfiedRange
from _emerge.emergelog import emergelog
from _emerge.is_valid_package_atom import is_valid_package_atom
from _emerge.main import profile_check
from _emerge.MetadataRegen import MetadataRegen
from _emerge.Package import Package
from _emerge.ProgressHandler import ProgressHandler
from _emerge.RootConfig import RootConfig
from _emerge.Scheduler import Scheduler
from _emerge.search import search
from _emerge.SetArg import SetArg
from _emerge.show_invalid_depstring_notice import show_invalid_depstring_notice
from _emerge.unmerge import unmerge
from _emerge.UnmergeDepPriority import UnmergeDepPriority
from _emerge.UseFlagDisplay import pkg_use_display
from _emerge.UserQuery import UserQuery

if sys.hexversion >= 0x3000000:
	long = int
	_unicode = str
else:
	_unicode = unicode

def action_build(emerge_config, trees=DeprecationWarning,
	mtimedb=DeprecationWarning, myopts=DeprecationWarning,
	myaction=DeprecationWarning, myfiles=DeprecationWarning, spinner=None):

	if not isinstance(emerge_config, _emerge_config):
		warnings.warn("_emerge.actions.action_build() now expects "
			"an _emerge_config instance as the first parameter",
			DeprecationWarning, stacklevel=2)
		emerge_config = load_emerge_config(
			action=myaction, args=myfiles, trees=trees, opts=myopts)
		adjust_configs(emerge_config.opts, emerge_config.trees)

	settings, trees, mtimedb = emerge_config
	myopts = emerge_config.opts
	myaction = emerge_config.action
	myfiles = emerge_config.args

	if '--usepkgonly' not in myopts:
		old_tree_timestamp_warn(settings['PORTDIR'], settings)

	# It's best for config updates in /etc/portage to be processed
	# before we get here, so warn if they're not (bug #267103).
	chk_updated_cfg_files(settings['EROOT'], ['/etc/portage'])

	# 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
		for x in mergelist:
			if not (isinstance(x, list) and len(x) == 4):
				continue
			pkg_type, pkg_root, pkg_key, pkg_action = x
			if pkg_root not in trees:
				# Current $ROOT setting differs,
				# so the list must be stale.
				mergelist = None
				break
		if not mergelist:
			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 ("--ask", "--color", "--skipfirst", "--tree"):
			resume_opts.pop(opt, None)

		# Current options always override resume_opts.
		resume_opts.update(myopts)
		myopts.clear()
		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=[]
	buildpkgonly = "--buildpkgonly" in myopts
	pretend = "--pretend" in myopts
	fetchonly = "--fetchonly" in myopts or "--fetch-all-uri" in myopts
	ask = "--ask" in myopts
	enter_invalid = '--ask-enter-invalid' 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
	myparams = create_depgraph_params(myopts, myaction)
	mergelist_shown = False

	if pretend or fetchonly:
		# make the mtimedb readonly
		mtimedb.filename = None
	if '--digest' in myopts or 'digest' in settings.features:
		if '--digest' in myopts:
			msg = "The --digest option"
		else:
			msg = "The FEATURES=digest setting"

		msg += " 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")
		for line in textwrap.wrap(msg, 72):
			writemsg("%s%s\n" % (prefix, line))
		writemsg(prefix + "\n")

	if resume:
		favorites = mtimedb["resume"].get("favorites")
		if not isinstance(favorites, list):
			favorites = []

		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

		success = False
		mydepgraph = None
		try:
			success, mydepgraph, dropped_tasks = resume_depgraph(
				settings, trees, mtimedb, myopts, myparams, spinner)
		except (portage.exception.PackageNotFound,
			depgraph.UnsatisfiedResumeDep) as e:
			if isinstance(e, depgraph.UnsatisfiedResumeDep):
				mydepgraph = e.depgraph

			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 textwrap.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 textwrap.wrap(msg, 72):
					out.eerror(line)

		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, 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:
			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

		try:
			success, mydepgraph, favorites = backtrack_depgraph(
				settings, trees, myopts, myparams, myaction, myfiles, spinner)
		except portage.exception.PackageSetNotFound as e:
			root_config = trees[settings['EROOT']]['root_config']
			display_missing_pkg_set(root_config, e.value)
			return 1

		if success and mydepgraph.need_config_reload():
			load_emerge_config(emerge_config=emerge_config)
			adjust_configs(emerge_config.opts, emerge_config.trees)
			settings, trees, mtimedb = emerge_config

			# After config reload, the freshly instantiated binarytree
			# instances need to load remote metadata if --getbinpkg
			# is enabled. Use getbinpkg_refresh=False to use cached
			# metadata, since the cache is already fresh.
			if "--getbinpkg" in emerge_config.opts:
				for root_trees in emerge_config.trees.values():
					try:
						root_trees["bintree"].populate(
							getbinpkgs=True,
							getbinpkg_refresh=False)
					except ParseError as e:
						writemsg("\n\n!!!%s.\nSee make.conf(5) for more info.\n"
								 % e, noiselevel=-1)
						return 1

		if "--autounmask-only" in myopts:
			mydepgraph.display_problems()
			return 0

		if not success:
			mydepgraph.display_problems()
			return 1

	mergecount = None
	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(),
				favorites=favorites)
			mydepgraph.display_problems()
			mergelist_shown = True
			if retval != os.EX_OK:
				return retval
			prompt="Would you like to resume merging these packages?"
		else:
			retval = mydepgraph.display(
				mydepgraph.altlist(),
				favorites=favorites)
			mydepgraph.display_problems()
			mergelist_shown = True
			if retval != os.EX_OK:
				return retval
			mergecount=0
			for x in mydepgraph.altlist():
				if isinstance(x, Package) and x.operation == "merge":
					mergecount += 1

			prompt = None
			if mergecount==0:
				sets = trees[settings['EROOT']]['root_config'].sets
				world_candidates = None
				if "selective" in myparams 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 "selective" in myparams and \
					not oneshot and world_candidates:
					# Prompt later, inside saveNomergeFavorites.
					prompt = None
				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()
		uq = UserQuery(myopts)
		if prompt is not None and "--ask" in myopts and \
			uq.query(prompt, enter_invalid) == "No":
			print()
			print("Quitting.")
			print()
			return 128 + signal.SIGINT
		# Don't ask again (e.g. when auto-cleaning packages after merge)
		if mergecount != 0:
			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(),
				favorites=favorites)
			mydepgraph.display_problems()
			mergelist_shown = True
			if retval != os.EX_OK:
				return retval
		else:
			retval = mydepgraph.display(
				mydepgraph.altlist(),
				favorites=favorites)
			mydepgraph.display_problems()
			mergelist_shown = True
			if retval != os.EX_OK:
				return retval

	else:

		if not mergelist_shown:
			# If we haven't already shown the merge list above, at
			# least show warnings about missed updates and such.
			mydepgraph.display_problems()


		need_write_vardb = not Scheduler. \
			_opts_no_self_update.intersection(myopts)

		need_write_bindb = not any(x in myopts for x in
			("--fetchonly", "--fetch-all-uri",
			"--pretend", "--usepkgonly")) and \
			(any("buildpkg" in trees[eroot]["root_config"].
				settings.features for eroot in trees) or
			any("buildsyspkg" in trees[eroot]["root_config"].
				settings.features for eroot in trees))

		if need_write_bindb or need_write_vardb:

			eroots = set()
			ebuild_eroots = set()
			for x in mydepgraph.altlist():
				if isinstance(x, Package) and x.operation == "merge":
					eroots.add(x.root)
					if x.type_name == "ebuild":
						ebuild_eroots.add(x.root)

			for eroot in eroots:
				if need_write_vardb and \
					not trees[eroot]["vartree"].dbapi.writable:
					writemsg_level("!!! %s\n" %
						_("Read-only file system: %s") %
						trees[eroot]["vartree"].dbapi._dbroot,
						level=logging.ERROR, noiselevel=-1)
					return 1

				if need_write_bindb and eroot in ebuild_eroots and \
					("buildpkg" in trees[eroot]["root_config"].
					settings.features or
					"buildsyspkg" in trees[eroot]["root_config"].
					settings.features) and \
					not trees[eroot]["bintree"].dbapi.writable:
					writemsg_level("!!! %s\n" %
						_("Read-only file system: %s") %
						trees[eroot]["bintree"].pkgdir,
						level=logging.ERROR, noiselevel=-1)
					return 1

		if ("--resume" in myopts):
			favorites=mtimedb["resume"]["favorites"]

		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()

			mydepgraph.saveNomergeFavorites()

		if mergecount == 0:
			retval = os.EX_OK
		else:
			mergetask = Scheduler(settings, trees, mtimedb, myopts,
				spinner, favorites=favorites,
				graph_config=mydepgraph.schedulerGraph())

			del mydepgraph
			clear_caches(trees)

			retval = mergetask.merge()

			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['EROOT']]['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")

		return retval

def action_config(settings, trees, myopts, myfiles):
	enter_invalid = '--ask-enter-invalid' in myopts
	uq = UserQuery(myopts)
	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], allow_repo=True):
		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['EROOT']]['vartree'].dbapi.match(myfiles[0])
	except portage.exception.AmbiguousPackageName as 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 = uq.query("Selection?", enter_invalid, responses=options)
			if idx == "X":
				sys.exit(128 + signal.SIGINT)
			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 uq.query("Ready to configure %s?" % pkg, enter_invalid) == "No":
			sys.exit(128 + signal.SIGINT)
	else:
		print("Configuring pkg...")
	print()
	ebuildpath = trees[settings['EROOT']]['vartree'].dbapi.findname(pkg)
	mysettings = portage.config(clone=settings)
	vardb = trees[mysettings['EROOT']]['vartree'].dbapi
	debug = mysettings.get("PORTAGE_DEBUG") == "1"
	retval = portage.doebuild(ebuildpath, "config", settings=mysettings,
		debug=(settings.get("PORTAGE_DEBUG", "") == 1), cleanup=True,
		mydbapi = trees[settings['EROOT']]['vartree'].dbapi, tree="vartree")
	if retval == os.EX_OK:
		portage.doebuild(ebuildpath, "clean", settings=mysettings,
			debug=debug, mydbapi=vardb, tree="vartree")
	print()
	return retval

def action_depclean(settings, trees, ldpath_mtimes,
	myopts, action, myfiles, spinner, scheduler=None):
	# 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.

	msg = []
	if "preserve-libs" not in settings.features and \
		not myopts.get("--depclean-lib-check", _DEPCLEAN_LIB_CHECK_DEFAULT) != "n":
		msg.append("Depclean may break link level dependencies. Thus, it is\n")
		msg.append("recommended to use a tool such as " + good("`revdep-rebuild`") + " (from\n")
		msg.append("app-portage/gentoolkit) in order to detect such breakage.\n")
		msg.append("\n")
	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 of this, it often becomes necessary to run \n")
	msg.append("%s" % good("`emerge --update --newuse --deep @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)

	root_config = trees[settings['EROOT']]['root_config']
	vardb = root_config.trees['vartree'].dbapi

	args_set = InternalPackageSet(allow_repo=True)
	if myfiles:
		args_set.update(myfiles)
		matched_packages = False
		for x in args_set:
			if vardb.match(x):
				matched_packages = True
			else:
				writemsg_level("--- Couldn't find '%s' to %s.\n" % \
					(x.replace("null/", ""), action),
					level=logging.WARN, noiselevel=-1)
		if not matched_packages:
			writemsg_level(">>> No packages selected for removal by %s\n" % \
				action)
			return 0

	# The calculation is done in a separate function so that depgraph
	# references go out of scope and the corresponding memory
	# is freed before we call unmerge().
	rval, cleanlist, ordered, req_pkg_count = \
		calc_depclean(settings, trees, ldpath_mtimes,
			myopts, action, args_set, spinner)

	clear_caches(trees)

	if rval != os.EX_OK:
		return rval

	if cleanlist:
		rval = unmerge(root_config, myopts, "unmerge",
			cleanlist, ldpath_mtimes, ordered=ordered,
			scheduler=scheduler)

	if action == "prune":
		return rval

	if not cleanlist and "--quiet" in myopts:
		return rval

	set_atoms = {}
	for k in ("profile", "system", "selected"):
		try:
			set_atoms[k] = root_config.setconfig.getSetAtoms(k)
		except portage.exception.PackageSetNotFound:
			# A nested set could not be resolved, so ignore nested sets.
			set_atoms[k] = root_config.sets[k].getAtoms()

	print("Packages installed:   " + str(len(vardb.cpv_all())))
	print("Packages in world:    %d" % len(set_atoms["selected"]))
	print("Packages in system:   %d" % len(set_atoms["system"]))
	if set_atoms["profile"]:
		print("Packages in profile:  %d" % len(set_atoms["profile"]))
	print("Required packages:    "+str(req_pkg_count))
	if "--pretend" in myopts:
		print("Number to remove:     "+str(len(cleanlist)))
	else:
		print("Number removed:       "+str(len(cleanlist)))

	return rval

def calc_depclean(settings, trees, ldpath_mtimes,
	myopts, action, args_set, spinner):
	allow_missing_deps = bool(args_set)

	debug = '--debug' in myopts
	xterm_titles = "notitles" not in settings.features
	root_len = len(settings["ROOT"])
	eroot = settings['EROOT']
	root_config = trees[eroot]["root_config"]
	psets = root_config.setconfig.psets
	deselect = myopts.get('--deselect') != 'n'
	required_sets = {}
	required_sets['world'] = psets['world']

	# When removing packages, a temporary version of the world 'selected'
	# set may be used which excludes packages that are intended to be
	# eligible for removal.
	selected_set = psets['selected']
	required_sets['selected'] = selected_set
	protected_set = InternalPackageSet()
	protected_set_name = '____depclean_protected_set____'
	required_sets[protected_set_name] = protected_set

	set_error = False
	set_atoms = {}
	for k in ("profile", "system", "selected"):
		try:
			set_atoms[k] = root_config.setconfig.getSetAtoms(k)
		except portage.exception.PackageSetNotFound as e:
			# A nested set could not be resolved, so ignore nested sets.
			set_atoms[k] = root_config.sets[k].getAtoms()
			writemsg_level(_("!!! The set '%s' "
				"contains a non-existent set named '%s'.\n") %
				(k, e), level=logging.ERROR, noiselevel=-1)
			set_error = True

	# Support @profile as an alternative to @system.
	if not (set_atoms["system"] or set_atoms["profile"]):
		writemsg_level(_("!!! You have no system list.\n"),
			level=logging.WARNING, noiselevel=-1)

	if not set_atoms["selected"]:
		writemsg_level(_("!!! You have no world file.\n"),
			level=logging.WARNING, noiselevel=-1)

	# Suppress world file warnings unless @world is completely empty,
	# since having an empty world file can be a valid state.
	try:
		world_atoms = bool(root_config.setconfig.getSetAtoms('world'))
	except portage.exception.PackageSetNotFound as e:
		writemsg_level(_("!!! The set '%s' "
			"contains a non-existent set named '%s'.\n") %
			("world", e), level=logging.ERROR, noiselevel=-1)
		set_error = True
	else:
		if not world_atoms:
			writemsg_level(_("!!! Your @world set is empty.\n"),
				level=logging.ERROR, noiselevel=-1)
			set_error = True

	if set_error:
		writemsg_level(_("!!! Aborting due to set configuration "
			"errors displayed above.\n"),
			level=logging.ERROR, noiselevel=-1)
		return 1, [], False, 0

	if action == "depclean":
		emergelog(xterm_titles, " >>> depclean")

	writemsg_level("\nCalculating dependencies  ")
	resolver_params = create_depgraph_params(myopts, "remove")
	resolver = depgraph(settings, trees, myopts, resolver_params, spinner)
	resolver._load_vdb()
	vardb = resolver._frozen_config.trees[eroot]["vartree"].dbapi
	real_vardb = trees[eroot]["vartree"].dbapi

	if action == "depclean":

		if args_set:

			if deselect:
				# Start with an empty set.
				selected_set = InternalPackageSet()
				required_sets['selected'] = selected_set
				# Pull in any sets nested within the selected set.
				selected_set.update(psets['selected'].getNonAtoms())

			# 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.
			for pkg in vardb:
				if spinner:
					spinner.update()

				try:
					if args_set.findAtomForPackage(pkg) is None:
						protected_set.add("=" + pkg.cpv)
						continue
				except portage.exception.InvalidDependString as e:
					show_invalid_depstring_notice(pkg, _unicode(e))
					del e
					protected_set.add("=" + pkg.cpv)
					continue

	elif action == "prune":

		if deselect:
			# Start with an empty set.
			selected_set = InternalPackageSet()
			required_sets['selected'] = selected_set
			# Pull in any sets nested within the selected set.
			selected_set.update(psets['selected'].getNonAtoms())

		# Pull in everything that's installed since we don't
		# to prune a package if something depends on it.
		protected_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:
			if spinner is not None:
				spinner.update()
			pkgs_for_cp = vardb.match_pkgs(Atom(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
				protected_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:
					protected_set.add("=" + pkg.cpv)
					continue
			except portage.exception.InvalidDependString as e:
				show_invalid_depstring_notice(pkg, _unicode(e))
				del e
				protected_set.add("=" + pkg.cpv)
				continue

	if resolver._frozen_config.excluded_pkgs:
		excluded_set = resolver._frozen_config.excluded_pkgs
		required_sets['__excluded__'] = InternalPackageSet()

		for pkg in vardb:
			if spinner:
				spinner.update()

			try:
				if excluded_set.findAtomForPackage(pkg):
					required_sets['__excluded__'].add("=" + pkg.cpv)
			except portage.exception.InvalidDependString as e:
				show_invalid_depstring_notice(pkg, _unicode(e))
				del e
				required_sets['__excluded__'].add("=" + pkg.cpv)

	success = resolver._complete_graph(required_sets={eroot:required_sets})
	writemsg_level("\b\b... done!\n")

	resolver.display_problems()

	if not success:
		return 1, [], False, 0

	def unresolved_deps():

		soname_deps = set()
		unresolvable = set()
		for dep in resolver._dynamic_config._initially_unsatisfied_deps:
			if isinstance(dep.parent, Package) and \
				(dep.priority > UnmergeDepPriority.SOFT):
				if dep.atom.soname:
					soname_deps.add((dep.atom, dep.parent.cpv))
				else:
					unresolvable.add((dep.atom, dep.parent.cpv))

		if soname_deps:
			# Generally, broken soname dependencies can safely be
			# suppressed by a REQUIRES_EXCLUDE setting in the ebuild,
			# so they should only trigger a warning message.
			prefix = warn(" * ")
			msg = []
			msg.append("Broken soname dependencies found:")
			msg.append("")
			for atom, parent in soname_deps:
				msg.append("  %s required by:" % (atom,))
				msg.append("    %s" % (parent,))
				msg.append("")

			writemsg_level("".join("%s%s\n" % (prefix, line) for line in msg),
				level=logging.WARNING, noiselevel=-1)

		if not unresolvable:
			return False

		if unresolvable and not allow_missing_deps:

			if "--debug" in myopts:
				writemsg("\ndigraph:\n\n", noiselevel=-1)
				resolver._dynamic_config.digraph.debug_print()
				writemsg("\n", noiselevel=-1)

			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:
				# For readability, we want to display the atom with USE
				# conditionals evaluated whenever possible. However,
				# there is a very special case where the atom does not
				# match because the unevaluated form contains one or
				# more flags for which the target package has missing
				# IUSE, but due to conditionals those flags are only
				# visible in the unevaluated form of the atom. In this
				# case, we must display the unevaluated atom, so that
				# the user can see the conditional USE deps that would
				# otherwise be invisible. Use Atom(_unicode(atom)) to
				# test for a package where this case would matter. This
				# is not necessarily the same as atom.without_use,
				# since Atom(_unicode(atom)) may still contain some
				# USE dependencies that remain after evaluation of
				# conditionals.
				if atom.package and atom != atom.unevaluated_atom and \
					vardb.match(Atom(_unicode(atom))):
					msg.append("  %s (%s) pulled in by:" %
						(atom.unevaluated_atom, atom))
				else:
					msg.append("  %s pulled in by:" % (atom,))
				msg.append("    %s" % (parent,))
				msg.append("")
			msg.extend(textwrap.wrap(
				"Have you forgotten to do a complete update prior " + \
				"to depclean? The most comprehensive command for this " + \
				"purpose is as follows:", 65
			))
			msg.append("")
			msg.append("  " + \
				good("emerge --update --newuse --deep --with-bdeps=y @world"))
			msg.append("")
			msg.extend(textwrap.wrap(
				"Note that the --with-bdeps=y option is not required in " + \
				"many situations. Refer to the emerge manual page " + \
				"(run `man emerge`) for more information about " + \
				"--with-bdeps.", 65
			))
			msg.append("")
			msg.extend(textwrap.wrap(
				"Also, note that it may be necessary to manually uninstall " + \
				"packages that no longer exist in the repository, since " + \
				"it may not be possible to satisfy their dependencies.", 65
			))
			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, [], False, 0

	graph = resolver._dynamic_config.digraph.copy()
	required_pkgs_total = 0
	for node in graph:
		if isinstance(node, Package):
			required_pkgs_total += 1

	def show_parents(child_node):
		parent_atoms = \
			resolver._dynamic_config._parent_atoms.get(child_node, [])

		# Never display the special internal protected_set.
		parent_atoms = [parent_atom for parent_atom in parent_atoms
			if not (isinstance(parent_atom[0], SetArg) and
			parent_atom[0].name == protected_set_name)]

		if not parent_atoms:
			# 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_atom_dict = {}
		for parent, atom in parent_atoms:
			parent_atom_dict.setdefault(parent, []).append(atom)

		parent_strs = []
		for parent, atoms in parent_atom_dict.items():
			# Display package atoms and soname
			# atoms in separate groups.
			atoms = sorted(atoms, reverse=True,
				key=operator.attrgetter('package'))
			parent_strs.append("%s requires %s" %
				(getattr(parent, "cpv", parent),
				", ".join(_unicode(atom) for atom in atoms)))
		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 cmp_pkg_cpv(pkg1, pkg2):
		"""Sort Package instances by cpv."""
		if pkg1.cpv > pkg2.cpv:
			return 1
		elif pkg1.cpv == pkg2.cpv:
			return 0
		else:
			return -1

	def create_cleanlist():

		if "--debug" in myopts:
			writemsg("\ndigraph:\n\n", noiselevel=-1)
			graph.debug_print()
			writemsg("\n", noiselevel=-1)

		pkgs_to_remove = []

		if action == "depclean":
			if args_set:

				for pkg in sorted(vardb, key=cmp_sort_key(cmp_pkg_cpv)):
					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 sorted(vardb, key=cmp_sort_key(cmp_pkg_cpv)):
					if pkg not in graph:
						pkgs_to_remove.append(pkg)
					elif "--verbose" in myopts:
						show_parents(pkg)

		elif action == "prune":

			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()
	clean_set = set(cleanlist)

	depclean_lib_check = cleanlist and real_vardb._linkmap is not None and \
		myopts.get("--depclean-lib-check", _DEPCLEAN_LIB_CHECK_DEFAULT) != "n"
	preserve_libs = "preserve-libs" in settings.features
	preserve_libs_restrict = False

	if depclean_lib_check and preserve_libs:
		for pkg in cleanlist:
			if "preserve-libs" in pkg.restrict:
				preserve_libs_restrict = True
				break

	if depclean_lib_check and \
		(preserve_libs_restrict or not preserve_libs):

		# Check if any of these packages 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.
		linkmap = real_vardb._linkmap
		consumer_cache = {}
		provider_cache = {}
		consumer_map = {}

		writemsg_level(">>> Checking for lib consumers...\n")

		for pkg in cleanlist:

			if preserve_libs and "preserve-libs" not in pkg.restrict:
				# Any needed libraries will be preserved
				# when this package is unmerged, so there's
				# no need to account for it here.
				continue

			pkg_dblink = real_vardb._dblink(pkg.cpv)
			consumers = {}

			for lib in pkg_dblink.getcontents():
				lib = lib[root_len:]
				lib_key = linkmap._obj_key(lib)
				lib_consumers = consumer_cache.get(lib_key)
				if lib_consumers is None:
					try:
						lib_consumers = linkmap.findConsumers(lib_key)
					except KeyError:
						continue
					consumer_cache[lib_key] = lib_consumers
				if lib_consumers:
					consumers[lib_key] = lib_consumers

			if not consumers:
				continue

			for lib, lib_consumers in list(consumers.items()):
				for consumer_file in list(lib_consumers):
					if pkg_dblink.isowner(consumer_file):
						lib_consumers.remove(consumer_file)
				if not lib_consumers:
					del consumers[lib]

			if not consumers:
				continue

			for lib, lib_consumers in consumers.items():

				soname = linkmap.getSoname(lib)

				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.values():
				for lib, consumer_providers in consumers.items():
					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 = {}
			for f in search_files:
				owner_set = set()
				for owner in linkmap.getOwners(f):
					owner_dblink = real_vardb._dblink(owner)
					if owner_dblink.exists():
						owner_set.add(owner_dblink)
				if owner_set:
					file_owners[f] = owner_set

			for pkg, consumers in list(consumer_map.items()):
				for lib, consumer_providers in list(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:
								provider_pkg = resolver._pkg(
									provider_dblink.mycpv, "installed",
									root_config, installed=True)
								if provider_pkg not in clean_set:
									provider_pkgs.add(provider_pkg)

						if provider_pkgs:
							continue

						if owner_set is not None:
							lib_consumers.update(owner_set)

					for consumer_dblink in list(lib_consumers):
						if resolver._pkg(consumer_dblink.mycpv, "installed",
							root_config, installed=True) 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(" * ")
			writemsg_level("".join(prefix + "%s\n" % line for \
				line in textwrap.wrap(msg, 70)), level=logging.WARNING, noiselevel=-1)

			msg = []
			for pkg in sorted(consumer_map, key=cmp_sort_key(cmp_pkg_cpv)):
				consumers = consumer_map[pkg]
				consumer_libs = {}
				for lib, lib_consumers in consumers.items():
					for consumer in lib_consumers:
						consumer_libs.setdefault(
							consumer.mycpv, set()).add(linkmap.getSoname(lib))
				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:
					libs = consumer_libs[consumer]
					msg.append("    %s needs %s" % \
						(consumer, ', '.join(sorted(libs))))
			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.items():
				for consumer_dblink in set(chain(*consumers.values())):
					consumer_pkg = resolver._pkg(consumer_dblink.mycpv,
						"installed", root_config, installed=True)
					if not resolver._add_pkg(pkg,
						Dependency(parent=consumer_pkg,
						priority=UnmergeDepPriority(runtime=True,
							runtime_slot_op=True),
						root=pkg.root)):
						resolver.display_problems()
						return 1, [], False, 0

			writemsg_level("\nCalculating dependencies  ")
			success = resolver._complete_graph(
				required_sets={eroot:required_sets})
			writemsg_level("\b\b... done!\n")
			resolver.display_problems()
			if not success:
				return 1, [], False, 0
			if unresolved_deps():
				return 1, [], False, 0

			graph = resolver._dynamic_config.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, [], False, required_pkgs_total
			clean_set = set(cleanlist)

	if clean_set:
		writemsg_level(">>> Calculating removal order...\n")
		# 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[:]

		runtime = UnmergeDepPriority(runtime=True)
		runtime_post = UnmergeDepPriority(runtime_post=True)
		buildtime = UnmergeDepPriority(buildtime=True)
		priority_map = {
			"RDEPEND": runtime,
			"PDEPEND": runtime_post,
			"BDEPEND": buildtime,
			"HDEPEND": buildtime,
			"DEPEND": buildtime,
		}

		for node in clean_set:
			graph.add(node, None)
			for dep_type in Package._dep_keys:
				depstr = node._metadata[dep_type]
				if not depstr:
					continue
				priority = priority_map[dep_type]

				if debug:
					writemsg_level("\nParent:    %s\n"
						% (node,), noiselevel=-1, level=logging.DEBUG)
					writemsg_level(  "Depstring: %s\n"
						% (depstr,), noiselevel=-1, level=logging.DEBUG)
					writemsg_level(  "Priority:  %s\n"
						% (priority,), noiselevel=-1, level=logging.DEBUG)

				try:
					atoms = resolver._select_atoms(eroot, depstr,
						myuse=node.use.enabled, parent=node,
						priority=priority)[node]
				except portage.exception.InvalidDependString:
					# Ignore invalid deps of packages that will
					# be uninstalled anyway.
					continue

				if debug:
					writemsg_level("Candidates: [%s]\n" % \
						', '.join("'%s'" % (x,) for x in atoms),
						noiselevel=-1, level=logging.DEBUG)

				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:

							mypriority = priority.copy()
							if atom.slot_operator_built:
								if mypriority.buildtime:
									mypriority.buildtime_slot_op = True
								if mypriority.runtime:
									mypriority.runtime_slot_op = True

							graph.add(child_node, node, priority=mypriority)

		if debug:
			writemsg_level("\nunmerge digraph:\n\n",
				noiselevel=-1, level=logging.DEBUG)
			graph.debug_print()
			writemsg_level("\n", noiselevel=-1, level=logging.DEBUG)

		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 (this can help minimize issues
			# with unaccounted implicit dependencies).
			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(key=cmp_sort_key(cmp_reference_count))

			ignore_priority_range = [None]
			ignore_priority_range.extend(
				range(UnmergeDepPriority.MIN, UnmergeDepPriority.MAX + 1))
			while graph:
				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 to minimize the number that
					# are dropped.
					del nodes[1:]
				for node in nodes:
					graph.remove(node)
					cleanlist.append(node.cpv)

		return 0, cleanlist, ordered, required_pkgs_total
	return 0, [], False, required_pkgs_total

def action_deselect(settings, trees, opts, atoms):
	enter_invalid = '--ask-enter-invalid' in opts
	root_config = trees[settings['EROOT']]['root_config']
	world_set = root_config.sets['selected']
	if not hasattr(world_set, 'update'):
		writemsg_level("World @selected set does not appear to be mutable.\n",
			level=logging.ERROR, noiselevel=-1)
		return 1

	pretend = '--pretend' in opts
	locked = False
	if not pretend and hasattr(world_set, 'lock'):
		world_set.lock()
		locked = True
	try:
		world_set.load()
		world_atoms = world_set.getAtoms()
		vardb = root_config.trees["vartree"].dbapi
		expanded_atoms = set(atoms)

		for atom in atoms:
			if not atom.startswith(SETPREFIX):
				if atom.cp.startswith("null/"):
					# try to expand category from world set
					null_cat, pn = portage.catsplit(atom.cp)
					for world_atom in world_atoms:
						cat, world_pn = portage.catsplit(world_atom.cp)
						if pn == world_pn:
							expanded_atoms.add(
								Atom(atom.replace("null", cat, 1),
								allow_repo=True, allow_wildcard=True))

				for cpv in vardb.match(atom):
					pkg = vardb._pkg_str(cpv, None)
					expanded_atoms.add(Atom("%s:%s" % (pkg.cp, pkg.slot)))

		discard_atoms = set()
		for atom in world_set:
			for arg_atom in expanded_atoms:
				if arg_atom.startswith(SETPREFIX):
					if atom.startswith(SETPREFIX) and \
						arg_atom == atom:
						discard_atoms.add(atom)
						break
				else:
					if not atom.startswith(SETPREFIX) and \
						arg_atom.intersects(atom) and \
						not (arg_atom.slot and not atom.slot) and \
						not (arg_atom.repo and not atom.repo):
						discard_atoms.add(atom)
						break
		if discard_atoms:
			for atom in sorted(discard_atoms):

				if pretend:
					action_desc = "Would remove"
				else:
					action_desc = "Removing"

				if atom.startswith(SETPREFIX):
					filename = "world_sets"
				else:
					filename = "world"

				writemsg_stdout(
					">>> %s %s from \"%s\" favorites file...\n" %
					(action_desc, colorize("INFORM", _unicode(atom)),
					filename), noiselevel=-1)

			if '--ask' in opts:
				prompt = "Would you like to remove these " + \
					"packages from your world favorites?"
				uq = UserQuery(opts)
				if uq.query(prompt, enter_invalid) == 'No':
					return 128 + signal.SIGINT

			remaining = set(world_set)
			remaining.difference_update(discard_atoms)
			if not pretend:
				world_set.replace(remaining)
		else:
			print(">>> No matching atoms found in \"world\" favorites file...")
	finally:
		if locked:
			world_set.unlock()
	return os.EX_OK

class _info_pkgs_ver(object):
	def __init__(self, ver, repo_suffix, provide_suffix):
		self.ver = ver
		self.repo_suffix = repo_suffix
		self.provide_suffix = provide_suffix

	def __lt__(self, other):
		return portage.versions.vercmp(self.ver, other.ver) < 0

	def toString(self):
		"""
		This may return unicode if repo_name contains unicode.
		Don't use __str__ and str() since unicode triggers compatibility
		issues between python 2.x and 3.x.
		"""
		return self.ver + self.repo_suffix + self.provide_suffix

def action_info(settings, trees, myopts, myfiles):

	# See if we can find any packages installed matching the strings
	# passed on the command line
	mypkgs = []
	eroot = settings['EROOT']
	vardb = trees[eroot]["vartree"].dbapi
	portdb = trees[eroot]['porttree'].dbapi
	bindb = trees[eroot]["bintree"].dbapi
	repos = portdb.settings.repositories
	for x in myfiles:
		any_match = False
		cp_exists = bool(vardb.match(x.cp))
		installed_match = vardb.match(x)
		for installed in installed_match:
			mypkgs.append((installed, "installed"))
			any_match = True

		if any_match:
			continue

		for db, pkg_type in ((portdb, "ebuild"), (bindb, "binary")):
			if pkg_type == "binary" and "--usepkg" not in myopts:
				continue

			# Use match instead of cp_list, to account for old-style virtuals.
			if not cp_exists and db.match(x.cp):
				cp_exists = True
			# Search for masked packages too.
			if not cp_exists and hasattr(db, "xmatch") and \
				db.xmatch("match-all", x.cp):
				cp_exists = True

			matches = db.match(x)
			matches.reverse()
			for match in matches:
				if pkg_type == "binary":
					if db.bintree.isremote(match):
						continue
				auxkeys = ["EAPI", "DEFINED_PHASES"]
				metadata = dict(zip(auxkeys, db.aux_get(match, auxkeys)))
				if metadata["EAPI"] not in ("0", "1", "2", "3") and \
					"info" in metadata["DEFINED_PHASES"].split():
					mypkgs.append((match, pkg_type))
					break

		if not cp_exists:
			xinfo = '"%s"' % x.unevaluated_atom
			# Discard null/ from failed cpv_expand category expansion.
			xinfo = xinfo.replace("null/", "")
			if settings["ROOT"] != "/":
				xinfo = "%s for %s" % (xinfo, eroot)
			writemsg("\nemerge: there are no ebuilds to satisfy %s.\n" %
				colorize("INFORM", xinfo), noiselevel=-1)

			if myopts.get("--misspell-suggestions", "y") != "n":

				writemsg("\nemerge: searching for similar names..."
					, noiselevel=-1)

				search_index = myopts.get("--search-index", "y") != "n"
				dbs = [IndexedVardb(vardb) if search_index else vardb]
				#if "--usepkgonly" not in myopts:
				dbs.append(IndexedPortdb(portdb) if search_index else portdb)
				if "--usepkg" in myopts:
					dbs.append(bindb)

				matches = similar_name_search(dbs, x)

				if len(matches) == 1:
					writemsg("\nemerge: Maybe you meant " + matches[0] + "?\n"
						, noiselevel=-1)
				elif len(matches) > 1:
					writemsg(
						"\nemerge: Maybe you meant any of these: %s?\n" % \
						(", ".join(matches),), noiselevel=-1)
				else:
					# Generally, this would only happen if
					# all dbapis are empty.
					writemsg(" nothing similar found.\n"
						, noiselevel=-1)

			return 1

	output_buffer = []
	append = output_buffer.append
	root_config = trees[settings['EROOT']]['root_config']
	chost = settings.get("CHOST")

	append(getportageversion(settings["PORTDIR"], None,
		settings.profile_path, chost,
		trees[settings['EROOT']]["vartree"].dbapi))

	header_width = 65
	header_title = "System Settings"
	if myfiles:
		append(header_width * "=")
		append(header_title.rjust(int(header_width/2 + len(header_title)/2)))
	append(header_width * "=")
	append("System uname: %s" % (platform.platform(aliased=1),))

	vm_info = get_vm_info()
	if "ram.total" in vm_info:
		line = "%-9s %10d total" % ("KiB Mem:", vm_info["ram.total"] // 1024)
		if "ram.free" in vm_info:
			line += ",%10d free" % (vm_info["ram.free"] // 1024,)
		append(line)
	if "swap.total" in vm_info:
		line = "%-9s %10d total" % ("KiB Swap:", vm_info["swap.total"] // 1024)
		if "swap.free" in vm_info:
			line += ",%10d free" % (vm_info["swap.free"] // 1024,)
		append(line)

	for repo in repos:
		last_sync = portage.grabfile(os.path.join(repo.location, "metadata", "timestamp.chk"))
		head_commit = None
		if last_sync:
			append("Timestamp of repository %s: %s" % (repo.name, last_sync[0]))
		if repo.sync_type:
			sync = portage.sync.module_controller.get_class(repo.sync_type)()
			options = { 'repo': repo }
			try:
				head_commit = sync.retrieve_head(options=options)
			except NotImplementedError:
				head_commit = (1, False)
		if head_commit and head_commit[0] == os.EX_OK:
			append("Head commit of repository %s: %s" % (repo.name, head_commit[1]))

	# Searching contents for the /bin/sh provider is somewhat
	# slow. Therefore, use the basename of the symlink target
	# to locate the package. If this fails, then only the
	# basename of the symlink target will be displayed. So,
	# typical output is something like "sh bash 4.2_p53". Since
	# realpath is used to resolve symlinks recursively, this
	# approach is also able to handle multiple levels of symlinks
	# such as /bin/sh -> bb -> busybox. Note that we do not parse
	# the output of "/bin/sh --version" because many shells
	# do not have a --version option.
	basename = os.path.basename(os.path.realpath(os.path.join(
		os.sep, portage.const.EPREFIX, "bin", "sh")))
	try:
		Atom("null/%s" % basename)
	except InvalidAtom:
		matches = None
	else:
		try:
			# Try a match against the basename, which should work for
			# busybox and most shells.
			matches = (trees[trees._running_eroot]["vartree"].dbapi.
				match(basename))
		except portage.exception.AmbiguousPackageName:
			# If the name is ambiguous, then restrict our match
			# to the app-shells category.
			matches = (trees[trees._running_eroot]["vartree"].dbapi.
				match("app-shells/%s" % basename))

	if matches:
		pkg = matches[-1]
		name = pkg.cp
		version = pkg.version
		# Omit app-shells category from the output.
		if name.startswith("app-shells/"):
			name = name[len("app-shells/"):]
		sh_str = "%s %s" % (name, version)
	else:
		sh_str = basename

	append("sh %s" % sh_str)

	ld_names = []
	if chost:
		ld_names.append(chost + "-ld")
	ld_names.append("ld")
	for name in ld_names:
		try:
			proc = subprocess.Popen([name, "--version"],
				stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
		except OSError:
			pass
		else:
			output = _unicode_decode(proc.communicate()[0]).splitlines()
			proc.wait()
			if proc.wait() == os.EX_OK and output:
				append("ld %s" % (output[0]))
				break

	try:
		proc = subprocess.Popen(["distcc", "--version"],
			stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
	except OSError:
		output = (1, None)
	else:
		output = _unicode_decode(proc.communicate()[0]).rstrip("\n")
		output = (proc.wait(), output)
	if output[0] == os.EX_OK:
		distcc_str = output[1].split("\n", 1)[0]
		if "distcc" in settings.features:
			distcc_str += " [enabled]"
		else:
			distcc_str += " [disabled]"
		append(distcc_str)

	try:
		proc = subprocess.Popen(["ccache", "-V"],
			stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
	except OSError:
		output = (1, None)
	else:
		output = _unicode_decode(proc.communicate()[0]).rstrip("\n")
		output = (proc.wait(), output)
	if output[0] == os.EX_OK:
		ccache_str = output[1].split("\n", 1)[0]
		if "ccache" in settings.features:
			ccache_str += " [enabled]"
		else:
			ccache_str += " [disabled]"
		append(ccache_str)

	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")
	atoms = []
	for x in myvars:
		try:
			x = Atom(x)
		except InvalidAtom:
			append("%-20s %s" % (x+":", "[NOT VALID]"))
		else:
			for atom in expand_new_virt(vardb, x):
				if not atom.blocker:
					atoms.append((x, atom))

	myvars = sorted(set(atoms))

	cp_map = {}
	cp_max_len = 0

	for orig_atom, x in myvars:
			pkg_matches = vardb.match(x)

			versions = []
			for cpv in pkg_matches:
				matched_cp = portage.versions.cpv_getkey(cpv)
				ver = portage.versions.cpv_getversion(cpv)
				ver_map = cp_map.setdefault(matched_cp, {})
				prev_match = ver_map.get(ver)
				if prev_match is not None:
					if prev_match.provide_suffix:
						# prefer duplicate matches that include
						# additional virtual provider info
						continue

				if len(matched_cp) > cp_max_len:
					cp_max_len = len(matched_cp)
				repo = vardb.aux_get(cpv, ["repository"])[0]
				if repo:
					repo_suffix = _repo_separator + repo
				else:
					repo_suffix = _repo_separator + "<unknown repository>"

				if matched_cp == orig_atom.cp:
					provide_suffix = ""
				else:
					provide_suffix = " (%s)" % (orig_atom,)

				ver_map[ver] = _info_pkgs_ver(ver, repo_suffix, provide_suffix)

	for cp in sorted(cp_map):
		versions = sorted(cp_map[cp].values())
		versions = ", ".join(ver.toString() for ver in versions)
		append("%s %s" % \
			((cp + ":").ljust(cp_max_len + 1), versions))

	append("Repositories:\n")
	for repo in repos:
		append(repo.info_string())

	installed_sets = sorted(s for s in
		root_config.sets['selected'].getNonAtoms() if s.startswith(SETPREFIX))
	if installed_sets:
		sets_line = "Installed sets: "
		sets_line += ", ".join(installed_sets)
		append(sets_line)

	if "--verbose" in myopts:
		myvars = list(settings)
	else:
		myvars = ['GENTOO_MIRRORS', 'CONFIG_PROTECT', 'CONFIG_PROTECT_MASK',
		          'DISTDIR', 'ENV_UNSET', 'PKGDIR', 'PORTAGE_TMPDIR',
		          'PORTAGE_BINHOST', 'PORTAGE_BUNZIP2_COMMAND',
		          'PORTAGE_BZIP2_COMMAND',
		          'USE', 'CHOST', 'CFLAGS', 'CXXFLAGS',
		          'ACCEPT_KEYWORDS', 'ACCEPT_LICENSE', 'FEATURES',
		          'EMERGE_DEFAULT_OPTS']

		myvars.extend(portage.util.grabfile(settings["PORTDIR"]+"/profiles/info_vars"))

	myvars_ignore_defaults = {
		'PORTAGE_BZIP2_COMMAND' : 'bzip2',
	}

	skipped_vars = ['PORTAGE_REPOSITORIES']
	# Deprecated variables
	skipped_vars.extend(('PORTDIR', 'PORTDIR_OVERLAY', 'SYNC'))

	myvars = set(myvars)
	myvars.difference_update(skipped_vars)
	myvars = sorted(myvars)

	use_expand = settings.get('USE_EXPAND', '').split()
	use_expand.sort()
	unset_vars = []

	for k in myvars:
		v = settings.get(k)
		if v is not None:
			if k != "USE":
				default = myvars_ignore_defaults.get(k)
				if default is not None and \
					default == v:
					continue
				append('%s="%s"' % (k, v))
			else:
				use = set(v.split())
				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()
				use = ['USE="%s"' % " ".join(use)]
				for varname in use_expand:
					myval = settings.get(varname)
					if myval:
						use.append('%s="%s"' % (varname, myval))
				append(" ".join(use))
		else:
			unset_vars.append(k)
	if unset_vars:
		append("Unset:  "+", ".join(unset_vars))
	append("")
	append("")
	writemsg_stdout("\n".join(output_buffer),
		noiselevel=-1)
	del output_buffer[:]

	# 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 + list(vardb._aux_cache_keys)
		auxkeys.append('DEFINED_PHASES')
		pkgsettings = portage.config(clone=settings)

		# Loop through each package
		# Only print settings if they differ from global settings
		header_title = "Package Settings"
		append(header_width * "=")
		append(header_title.rjust(int(header_width/2 + len(header_title)/2)))
		append(header_width * "=")
		append("")
		writemsg_stdout("\n".join(output_buffer),
			noiselevel=-1)
		del output_buffer[:]

		out = portage.output.EOutput()
		for mypkg in mypkgs:
			cpv = mypkg[0]
			pkg_type = mypkg[1]
			# Get all package specific variables
			if pkg_type == "installed":
				metadata = dict(zip(auxkeys, vardb.aux_get(cpv, auxkeys)))
			elif pkg_type == "ebuild":
				metadata = dict(zip(auxkeys, portdb.aux_get(cpv, auxkeys)))
			elif pkg_type == "binary":
				metadata = dict(zip(auxkeys, bindb.aux_get(cpv, auxkeys)))

			pkg = Package(built=(pkg_type!="ebuild"), cpv=cpv,
				installed=(pkg_type=="installed"), metadata=zip(Package.metadata_keys,
				(metadata.get(x, '') for x in Package.metadata_keys)),
				root_config=root_config, type_name=pkg_type)

			if pkg_type == "installed":
				append("\n%s was built with the following:" % \
					colorize("INFORM", str(pkg.cpv + _repo_separator + pkg.repo)))
			elif pkg_type == "ebuild":
				append("\n%s would be built with the following:" % \
					colorize("INFORM", str(pkg.cpv + _repo_separator + pkg.repo)))
			elif pkg_type == "binary":
				append("\n%s (non-installed binary) was built with the following:" % \
					colorize("INFORM", str(pkg.cpv + _repo_separator + pkg.repo)))

			append('%s' % pkg_use_display(pkg, myopts))
			if pkg_type == "installed":
				for myvar in mydesiredvars:
					if metadata[myvar].split() != settings.get(myvar, '').split():
						append("%s=\"%s\"" % (myvar, metadata[myvar]))
			append("")
			append("")
			writemsg_stdout("\n".join(output_buffer),
				noiselevel=-1)
			del output_buffer[:]

			if metadata['DEFINED_PHASES']:
				if 'info' not in metadata['DEFINED_PHASES'].split():
					continue

			writemsg_stdout(">>> Attempting to run pkg_info() for '%s'\n"
				% pkg.cpv, noiselevel=-1)

			if pkg_type == "installed":
				ebuildpath = vardb.findname(pkg.cpv)
			elif pkg_type == "ebuild":
				ebuildpath = portdb.findname(pkg.cpv, myrepo=pkg.repo)
			elif pkg_type == "binary":
				tbz2_file = bindb.bintree.getname(pkg.cpv)
				ebuild_file_name = pkg.cpv.split("/")[1] + ".ebuild"
				ebuild_file_contents = portage.xpak.tbz2(tbz2_file).getfile(ebuild_file_name)
				tmpdir = tempfile.mkdtemp()
				ebuildpath = os.path.join(tmpdir, ebuild_file_name)
				file = open(ebuildpath, 'w')
				file.write(ebuild_file_contents)
				file.close()

			if not ebuildpath or not os.path.exists(ebuildpath):
				out.ewarn("No ebuild found for '%s'" % pkg.cpv)
				continue

			if pkg_type == "installed":
				portage.doebuild(ebuildpath, "info", settings=pkgsettings,
					debug=(settings.get("PORTAGE_DEBUG", "") == 1),
					mydbapi=trees[settings['EROOT']]["vartree"].dbapi,
					tree="vartree")
			elif pkg_type == "ebuild":
				portage.doebuild(ebuildpath, "info", settings=pkgsettings,
					debug=(settings.get("PORTAGE_DEBUG", "") == 1),
					mydbapi=trees[settings['EROOT']]['porttree'].dbapi,
					tree="porttree")
			elif pkg_type == "binary":
				portage.doebuild(ebuildpath, "info", settings=pkgsettings,
					debug=(settings.get("PORTAGE_DEBUG", "") == 1),
					mydbapi=trees[settings['EROOT']]["bintree"].dbapi,
					tree="bintree")
				shutil.rmtree(tmpdir)

def action_regen(settings, portdb, max_jobs, max_load):
	xterm_titles = "notitles" not in settings.features
	emergelog(xterm_titles, " === regen")
	#regenerate cache entries
	sys.stdout.flush()

	regen = MetadataRegen(portdb, max_jobs=max_jobs,
		max_load=max_load, main=True)

	signum = run_main_scheduler(regen)
	if signum is not None:
		sys.exit(128 + signum)

	portage.writemsg_stdout("done!\n")
	return regen.returncode

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,
			search_index=myopts.get("--search-index", "y") != "n",
			search_similarity=myopts.get("--search-similarity"),
			fuzzy=myopts.get("--fuzzy-search") != "n",
			)
		for mysearch in myfiles:
			try:
				searchinstance.execute(mysearch)
			except re.error as comment:
				print("\n!!! Regular expression error in \"%s\": %s" % ( mysearch, comment ))
				sys.exit(1)
			searchinstance.output()

def action_sync(emerge_config, trees=DeprecationWarning,
	mtimedb=DeprecationWarning, opts=DeprecationWarning,
	action=DeprecationWarning):

	if not isinstance(emerge_config, _emerge_config):
		warnings.warn("_emerge.actions.action_sync() now expects "
			"an _emerge_config instance as the first parameter",
			DeprecationWarning, stacklevel=2)
		emerge_config = load_emerge_config(
			action=action, args=[], trees=trees, opts=opts)

	syncer = SyncRepos(emerge_config)
	return_messages = "--quiet" not in emerge_config.opts
	options = {'return-messages' : return_messages}
	if emerge_config.args:
		options['repo'] = emerge_config.args
		success, msgs = syncer.repo(options=options)
	else:
		success, msgs = syncer.auto_sync(options=options)
	if return_messages:
		print_results(msgs)

	return os.EX_OK if success else 1


def action_uninstall(settings, trees, ldpath_mtimes,
	opts, action, files, spinner):
	# For backward compat, some actions do not require leading '='.
	ignore_missing_eq = action in ('clean', 'rage-clean', 'unmerge')
	root = settings['ROOT']
	eroot = settings['EROOT']
	vardb = trees[settings['EROOT']]['vartree'].dbapi
	valid_atoms = []
	lookup_owners = []

	# Ensure atoms are valid before calling unmerge().
	# For backward compat, leading '=' is not required.
	for x in files:
		if is_valid_package_atom(x, allow_repo=True) or \
			(ignore_missing_eq and is_valid_package_atom('=' + x)):

			try:
				atom = dep_expand(x, mydb=vardb, settings=settings)
			except portage.exception.AmbiguousPackageName as 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.args[0]:
					writemsg_level("    %s\n" % colorize("INFORM", i),
						level=logging.ERROR, noiselevel=-1)
				writemsg_level("\n", level=logging.ERROR, noiselevel=-1)
				return 1
			else:
				if atom.use and atom.use.conditional:
					writemsg_level(
						("\n\n!!! '%s' contains a conditional " + \
						"which is not allowed.\n") % (x,),
						level=logging.ERROR, noiselevel=-1)
					writemsg_level(
						"!!! Please check ebuild(5) for full details.\n",
						level=logging.ERROR)
					return 1
				valid_atoms.append(atom)

		elif x.startswith(os.sep):
			if not x.startswith(eroot):
				writemsg_level(("!!! '%s' does not start with" + \
					" $EROOT.\n") % x, level=logging.ERROR, noiselevel=-1)
				return 1
			# Queue these up since it's most efficient to handle
			# multiple files in a single iter_owners() call.
			lookup_owners.append(x)

		elif x.startswith(SETPREFIX) and action == "deselect":
			valid_atoms.append(x)

		elif "*" in x:
			try:
				ext_atom = Atom(x, allow_repo=True, allow_wildcard=True)
			except InvalidAtom:
				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

			for cpv in vardb.cpv_all():
				if portage.match_from_list(ext_atom, [cpv]):
					require_metadata = False
					atom = portage.cpv_getkey(cpv)
					if ext_atom.operator == '=*':
						atom = "=" + atom + "-" + \
							portage.versions.cpv_getversion(cpv)
					if ext_atom.slot:
						atom += _slot_separator + ext_atom.slot
						require_metadata = True
					if ext_atom.repo:
						atom += _repo_separator + ext_atom.repo
						require_metadata = True

					atom = Atom(atom, allow_repo=True)
					if require_metadata:
						try:
							cpv = vardb._pkg_str(cpv, ext_atom.repo)
						except (KeyError, InvalidData):
							continue
						if not portage.match_from_list(atom, [cpv]):
							continue

					valid_atoms.append(atom)

		else:
			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 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(root)-1:])

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

		if owners:
			for cpv in owners:
				pkg = vardb._pkg_str(cpv, None)
				atom = '%s:%s' % (pkg.cp, pkg.slot)
				valid_atoms.append(portage.dep.Atom(atom))
		else:
			writemsg_level(("!!! '%s' is not claimed " + \
				"by any package.\n") % lookup_owners[0],
				level=logging.WARNING, noiselevel=-1)

	if files and not valid_atoms:
		return 1

	if action == 'unmerge' and \
		'--quiet' not in opts and \
		'--quiet-unmerge-warn' not in opts:
		msg = "This action can remove important packages! " + \
			"In order to be safer, use " + \
			"`emerge -pv --depclean <atom>` to check for " + \
			"reverse dependencies before removing packages."
		out = portage.output.EOutput()
		for line in textwrap.wrap(msg, 72):
			out.ewarn(line)

	if action == 'deselect':
		return action_deselect(settings, trees, opts, valid_atoms)

	# Use the same logic as the Scheduler class to trigger redirection
	# of ebuild pkg_prerm/postrm phase output to logs as appropriate
	# for options such as --jobs, --quiet and --quiet-build.
	max_jobs = opts.get("--jobs", 1)
	background = (max_jobs is True or max_jobs > 1 or
		"--quiet" in opts or opts.get("--quiet-build") == "y")
	sched_iface = SchedulerInterface(global_event_loop(),
		is_background=lambda: background)

	if background:
		settings.unlock()
		settings["PORTAGE_BACKGROUND"] = "1"
		settings.backup_changes("PORTAGE_BACKGROUND")
		settings.lock()

	if action in ('clean', 'rage-clean', 'unmerge') or \
		(action == 'prune' and "--nodeps" in opts):
		# When given a list of atoms, unmerge them in the order given.
		ordered = action in ('rage-clean', 'unmerge')
		rval = unmerge(trees[settings['EROOT']]['root_config'], opts, action,
			valid_atoms, ldpath_mtimes, ordered=ordered,
			scheduler=sched_iface)
	else:
		rval = action_depclean(settings, trees, ldpath_mtimes,
			opts, action, valid_atoms, spinner,
			scheduler=sched_iface)

	return rval

def adjust_configs(myopts, trees):
	for myroot, mytrees in trees.items():
		mysettings =  trees[myroot]["vartree"].settings
		mysettings.unlock()

		# For --usepkgonly mode, propagate settings from the binary package
		# database, so that it's possible to operate without dependence on
		# a local ebuild repository and profile.
		if ('--usepkgonly' in myopts and
			mytrees['bintree']._propagate_config(mysettings)):
			# Also propagate changes to the portdbapi doebuild_settings
			# attribute which is used by Package instances for USE
			# calculations (in support of --binpkg-respect-use).
			mytrees['porttree'].dbapi.doebuild_settings = \
				portage.config(clone=mysettings)

		adjust_config(myopts, mysettings)
		mysettings.lock()

def adjust_config(myopts, settings):
	"""Make emerge specific adjustments to the config."""

	# Kill noauto as it will break merges otherwise.
	if "noauto" in settings.features:
		settings.features.remove('noauto')

	fail_clean = myopts.get('--fail-clean')
	if fail_clean is not None:
		if fail_clean is True and \
			'fail-clean' not in settings.features:
			settings.features.add('fail-clean')
		elif fail_clean == 'n' and \
			'fail-clean' in settings.features:
			settings.features.remove('fail-clean')

	CLEAN_DELAY = 5
	try:
		CLEAN_DELAY = int(settings.get("CLEAN_DELAY", str(CLEAN_DELAY)))
	except ValueError as 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 as 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")

	buildpkg = myopts.get("--buildpkg")
	if buildpkg is True:
		settings.features.add("buildpkg")
	elif buildpkg == 'n':
		settings.features.discard("buildpkg")

	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 as 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 settings.get('TERM') == 'dumb' or \
		not sys.stdout.isatty():
		portage.output.havecolor = 0
		settings["NOCOLOR"] = "true"
		settings.backup_changes("NOCOLOR")

	if "--pkg-format" in myopts:
		settings["PORTAGE_BINPKG_FORMAT"] = myopts["--pkg-format"]
		settings.backup_changes("PORTAGE_BINPKG_FORMAT")

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 relative_profile_path(portdir, abs_profile):
	realpath = os.path.realpath(abs_profile)
	basepath   = os.path.realpath(os.path.join(portdir, "profiles"))
	if realpath.startswith(basepath):
		profilever = realpath[1 + len(basepath):]
	else:
		profilever = None
	return profilever

def getportageversion(portdir, _unused, profile, chost, vardb):
	pythonver = 'python %d.%d.%d-%s-%d' % sys.version_info[:]
	profilever = None
	repositories = vardb.settings.repositories
	if profile:
		profilever = relative_profile_path(portdir, profile)
		if profilever is None:
			try:
				for parent in portage.grabfile(
					os.path.join(profile, 'parent')):
					profilever = relative_profile_path(portdir,
						os.path.join(profile, parent))
					if profilever is not None:
						break
					colon = parent.find(":")
					if colon != -1:
						p_repo_name = parent[:colon]
						try:
							p_repo_loc = \
								repositories.get_location_for_name(p_repo_name)
						except KeyError:
							pass
						else:
							profilever = relative_profile_path(p_repo_loc,
								os.path.join(p_repo_loc, 'profiles',
									parent[colon+1:]))
							if profilever is not None:
								break
			except portage.exception.PortageException:
				pass

			if profilever is None:
				try:
					profilever = "!" + os.readlink(profile)
				except (OSError):
					pass

	if profilever is None:
		profilever = "unavailable"

	libcver = []
	libclist = set()
	for atom in expand_new_virt(vardb, portage.const.LIBC_PACKAGE_ATOM):
		if not atom.blocker:
			libclist.update(vardb.match(atom))
	if libclist:
		for cpv in sorted(libclist):
			libc_split = portage.catpkgsplit(cpv)[1:]
			if libc_split[-1] == "r0":
				libc_split = libc_split[:-1]
			libcver.append("-".join(libc_split))
	else:
		libcver = ["unavailable"]

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

	return "Portage %s (%s, %s, %s, %s, %s)" % \
		(portage.VERSION, pythonver, profilever, gccver, ",".join(libcver), unameout)


class _emerge_config(SlotObject):

	__slots__ = ('action', 'args', 'opts',
		'running_config', 'target_config', 'trees')

	# Support unpack as tuple, for load_emerge_config backward compatibility.
	def __iter__(self):
		yield self.target_config.settings
		yield self.trees
		yield self.target_config.mtimedb

	def __getitem__(self, index):
		return list(self)[index]

	def __len__(self):
		return 3

def load_emerge_config(emerge_config=None, env=None, **kargs):

	if emerge_config is None:
		emerge_config = _emerge_config(**kargs)

	env = os.environ if env is None else env
	kwargs = {'env': env}
	for k, envvar in (("config_root", "PORTAGE_CONFIGROOT"), ("target_root", "ROOT"),
			("sysroot", "SYSROOT"), ("eprefix", "EPREFIX")):
		v = env.get(envvar)
		if v and v.strip():
			kwargs[k] = v
	emerge_config.trees = portage.create_trees(trees=emerge_config.trees,
				**kwargs)

	for root_trees in emerge_config.trees.values():
		settings = root_trees["vartree"].settings
		settings._init_dirs()
		setconfig = load_default_config(settings, root_trees)
		root_config = RootConfig(settings, root_trees, setconfig)
		if "root_config" in root_trees:
			# Propagate changes to the existing instance,
			# which may be referenced by a depgraph.
			root_trees["root_config"].update(root_config)
		else:
			root_trees["root_config"] = root_config

	target_eroot = emerge_config.trees._target_eroot
	emerge_config.target_config = \
		emerge_config.trees[target_eroot]['root_config']
	emerge_config.target_config.mtimedb = portage.MtimeDB(
		os.path.join(target_eroot, portage.CACHE_PATH, "mtimedb"))
	emerge_config.running_config = emerge_config.trees[
		emerge_config.trees._running_eroot]['root_config']
	QueryCommand._db = emerge_config.trees

	return emerge_config

def getgccversion(chost=None):
	"""
	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"
	)

	if chost:
		try:
			proc = subprocess.Popen(["gcc-config", "-c"],
				stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
		except OSError:
			myoutput = None
			mystatus = 1
		else:
			myoutput = _unicode_decode(proc.communicate()[0]).rstrip("\n")
			mystatus = proc.wait()
		if mystatus == os.EX_OK and myoutput.startswith(chost + "-"):
			return myoutput.replace(chost + "-", gcc_ver_prefix, 1)

		try:
			proc = subprocess.Popen(
				[chost + "-" + gcc_ver_command[0]] + gcc_ver_command[1:],
				stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
		except OSError:
			myoutput = None
			mystatus = 1
		else:
			myoutput = _unicode_decode(proc.communicate()[0]).rstrip("\n")
			mystatus