text: #############################################################################
  #
  # Copyright (c) 2005 Zope Foundation and Contributors.
  # All Rights Reserved.
  #
  # This software is subject to the provisions of the Zope Public License,
  # Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
  # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
  # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
  # FOR A PARTICULAR PURPOSE.
  #
  ##############################################################################
  """Python easy_install API
  
  This module provides a high-level Python API for installing packages.
  It doesn't install scripts.  It uses setuptools and requires it to be
  installed.
  """
  
  import distutils.errors
  import errno
  import glob
  import logging
  import os
  import pkg_resources
  import py_compile
  import re
  import setuptools.archive_util
  import setuptools.command.easy_install
  import setuptools.command.setopt
  import setuptools.package_index
  import shutil
  import subprocess
  import sys
  import tempfile
  import zc.buildout
  
  _oprp = getattr(os.path, 'realpath', lambda path: path)
  def realpath(path):
      return os.path.normcase(os.path.abspath(_oprp(path)))
  
  default_index_url = os.environ.get(
      'buildout-testing-index-url',
      'http://pypi.python.org/simple',
      )
  
  logger = logging.getLogger('zc.buildout.easy_install')
  
  url_match = re.compile('[a-z0-9+.-]+://').match
  is_source_encoding_line = re.compile('coding[:=]\s*([-\w.]+)').search
  # Source encoding regex from http://www.python.org/dev/peps/pep-0263/
  
  is_win32 = sys.platform == 'win32'
  is_jython = sys.platform.startswith('java')
  
  if is_jython:
      import java.lang.System
      jython_os_name = (java.lang.System.getProperties()['os.name']).lower()
  
  # Make sure we're not being run with an older bootstrap.py that gives us
  # setuptools instead of setuptools
  has_distribute = pkg_resources.working_set.find(
          pkg_resources.Requirement.parse('distribute')) is not None
  has_setuptools = pkg_resources.working_set.find(
          pkg_resources.Requirement.parse('setuptools')) is not None
  if has_distribute and not has_setuptools:
      sys.exit("zc.buildout 2 needs setuptools, not distribute."
               "  Are you using an outdated bootstrap.py?  Make sure"
               " you have the latest version downloaded from"
               " http://downloads.buildout.org/2/bootstrap.py")
  
  setuptools_loc = pkg_resources.working_set.find(
      pkg_resources.Requirement.parse('setuptools')
      ).location
  
  # Include buildout and setuptools eggs in paths
  buildout_and_setuptools_path = [
      setuptools_loc,
      pkg_resources.working_set.find(
          pkg_resources.Requirement.parse('zc.buildout')).location,
      ]
  
  FILE_SCHEME = re.compile('file://', re.I).match
  
  class _Monkey(object):
      def __init__(self, module, **kw):
          mdict = self._mdict = module.__dict__
          self._before = mdict.copy()
          self._overrides = kw
  
      def __enter__(self):
          self._mdict.update(self._overrides)
          return self
  
      def __exit__(self, exc_type, exc_value, traceback):
          self._mdict.clear()
          self._mdict.update(self._before)
  
  class _NoWarn(object):
      def warn(self, *args, **kw):
          pass
  
  _no_warn = _NoWarn()
  
  class AllowHostsPackageIndex(setuptools.package_index.PackageIndex):
      """Will allow urls that are local to the system.
  
      No matter what is allow_hosts.
      """
      def url_ok(self, url, fatal=False):
          if FILE_SCHEME(url):
              return True
          # distutils has its own logging, which can't be hooked / suppressed,
          # so we monkey-patch the 'log' submodule to suppress the stupid
          # "Link to <URL> ***BLOCKED*** by --allow-hosts" message.
          with _Monkey(setuptools.package_index, log=_no_warn):
              return setuptools.package_index.PackageIndex.url_ok(
                                                  self, url, False)
  
  
  _indexes = {}
  def _get_index(index_url, find_links, allow_hosts=('*',)):
      key = index_url, tuple(find_links)
      index = _indexes.get(key)
      if index is not None:
          return index
  
      if index_url is None:
          index_url = default_index_url
      if index_url.startswith('file://'):
          index_url = index_url[7:]
      index = AllowHostsPackageIndex(index_url, hosts=allow_hosts)
  
      if find_links:
          index.add_find_links(find_links)
  
      _indexes[key] = index
      return index
  
  clear_index_cache = _indexes.clear
  
  if is_win32:
      # work around spawn lamosity on windows
      # XXX need safe quoting (see the subproces.list2cmdline) and test
      def _safe_arg(arg):
          return '"%s"' % arg
  else:
      _safe_arg = str
  
  def call_subprocess(args, **kw):
      if subprocess.call(args, **kw) != 0:
          raise Exception(
              "Failed to run command:\n%s"
              % repr(args)[1:-1])
  
  
  def _execute_permission():
      current_umask = os.umask(0o022)
      # os.umask only returns the current umask if you also give it one, so we
      # have to give it a dummy one and immediately set it back to the real
      # value...  Distribute does the same.
      os.umask(current_umask)
      return 0o777 - current_umask
  
  
  _easy_install_cmd = 'from setuptools.command.easy_install import main; main()'
  
  class Installer:
  
      _versions = {}
      _required_by = {}
      _picked_versions = {}
      _download_cache = None
      _install_from_cache = False
      _prefer_final = True
      _use_dependency_links = True
      _allow_picked_versions = True
      _store_required_by = False
  
      def __init__(self,
                   dest=None,
                   links=(),
                   index=None,
                   executable=sys.executable,
                   always_unzip=None, # Backward compat :/
                   path=None,
                   newest=True,
                   versions=None,
                   use_dependency_links=None,
                   allow_hosts=('*',)
                   ):
          assert executable == sys.executable, (executable, sys.executable)
          self._dest = dest
          self._allow_hosts = allow_hosts
  
          if self._install_from_cache:
              if not self._download_cache:
                  raise ValueError("install_from_cache set to true with no"
                                   " download cache")
              links = ()
              index = 'file://' + self._download_cache
  
          if use_dependency_links is not None:
              self._use_dependency_links = use_dependency_links
          self._links = links = list(_fix_file_links(links))
          if self._download_cache and (self._download_cache not in links):
              links.insert(0, self._download_cache)
  
          self._index_url = index
          path = (path and path[:] or []) + buildout_and_setuptools_path
          if dest is not None and dest not in path:
              path.insert(0, dest)
          self._path = path
          if self._dest is None:
              newest = False
          self._newest = newest
          self._env = pkg_resources.Environment(path)
          self._index = _get_index(index, links, self._allow_hosts)
  
          if versions is not None:
              self._versions = normalize_versions(versions)
  
      def _satisfied(self, req, source=None):
          dists = [dist for dist in self._env[req.project_name] if dist in req]
          if not dists:
              logger.debug('We have no distributions for %s that satisfies %r.',
                           req.project_name, str(req))
  
              return None, self._obtain(req, source)
  
          # Note that dists are sorted from best to worst, as promised by
          # env.__getitem__
  
          for dist in dists:
              if (dist.precedence == pkg_resources.DEVELOP_DIST):
                  logger.debug('We have a develop egg: %s', dist)
                  return dist, None
  
          # Special common case, we have a specification for a single version:
          specs = req.specs
          if len(specs) == 1 and specs[0][0] == '==':
              logger.debug('We have the distribution that satisfies %r.',
                           str(req))
              return dists[0], None
  
          if self._prefer_final:
              fdists = [dist for dist in dists
                        if _final_version(dist.parsed_version)
                        ]
              if fdists:
                  # There are final dists, so only use those
                  dists = fdists
  
          if not self._newest:
              # We don't need the newest, so we'll use the newest one we
              # find, which is the first returned by
              # Environment.__getitem__.
              return dists[0], None
  
          best_we_have = dists[0] # Because dists are sorted from best to worst
  
          # We have some installed distros.  There might, theoretically, be
          # newer ones.  Let's find out which ones are available and see if
          # any are newer.  We only do this if we're willing to install
          # something, which is only true if dest is not None:
  
          best_available = self._obtain(req, source)
  
          if best_available is None:
              # That's a bit odd.  There aren't any distros available.
              # We should use the best one we have that meets the requirement.
              logger.debug(
                  'There are no distros available that meet %r.\n'
                  'Using our best, %s.',
                  str(req), best_available)
              return best_we_have, None
  
          if self._prefer_final:
              if _final_version(best_available.parsed_version):
                  if _final_version(best_we_have.parsed_version):
                      if (best_we_have.parsed_version
                          <
                          best_available.parsed_version
                          ):
                          return None, best_available
                  else:
                      return None, best_available
              else:
                  if (not _final_version(best_we_have.parsed_version)
                      and
                      (best_we_have.parsed_version
                       <
                       best_available.parsed_version
                       )
                      ):
                      return None, best_available
          else:
              if (best_we_have.parsed_version
                  <
                  best_available.parsed_version
                  ):
                  return None, best_available
  
          logger.debug(
              'We have the best distribution that satisfies %r.',
              str(req))
          return best_we_have, None
  
      def _load_dist(self, dist):
          dists = pkg_resources.Environment(dist.location)[dist.project_name]
          assert len(dists) == 1
          return dists[0]
  
      def _call_easy_install(self, spec, ws, dest, dist):
  
          tmp = tempfile.mkdtemp(dir=dest)
          try:
              path = setuptools_loc
  
              args = [sys.executable, '-c', _easy_install_cmd, '-mZUNxd', tmp]
              level = logger.getEffectiveLevel()
              if level > 0:
                  args.append('-q')
              elif level < 0:
                  args.append('-v')
  
              args.append(spec)
  
              if level <= logging.DEBUG:
                  logger.debug('Running easy_install:\n"%s"\npath=%s\n',
                               '" "'.join(args), path)
  
              sys.stdout.flush() # We want any pending output first
  
              exit_code = subprocess.call(
                  list(args),
                  env=dict(os.environ, PYTHONPATH=path))
  
              dists = []
              env = pkg_resources.Environment([tmp])
              for project in env:
                  dists.extend(env[project])
  
              if exit_code:
                  logger.error(
                      "An error occurred when trying to install %s. "
                      "Look above this message for any errors that "
                      "were output by easy_install.",
                      dist)
  
              if not dists:
                  raise zc.buildout.UserError("Couldn't install: %s" % dist)
  
              if len(dists) > 1:
                  logger.warn("Installing %s\n"
                              "caused multiple distributions to be installed:\n"
                              "%s\n",
                              dist, '\n'.join(map(str, dists)))
              else:
                  d = dists[0]
                  if d.project_name != dist.project_name:
                      logger.warn("Installing %s\n"
                                  "Caused installation of a distribution:\n"
                                  "%s\n"
                                  "with a different project name.",
                                  dist, d)
                  if d.version != dist.version:
                      logger.warn("Installing %s\n"
                                  "Caused installation of a distribution:\n"
                                  "%s\n"
                                  "with a different version.",
                                  dist, d)
  
              result = []
              for d in dists:
                  newloc = os.path.join(dest, os.path.basename(d.location))
                  if os.path.exists(newloc):
                      if os.path.isdir(newloc):
                          shutil.rmtree(newloc)
                      else:
                          os.remove(newloc)
                  os.rename(d.location, newloc)
  
                  [d] = pkg_resources.Environment([newloc])[d.project_name]
  
                  result.append(d)
  
              return result
  
          finally:
              shutil.rmtree(tmp)
  
      def _obtain(self, requirement, source=None):
          # initialize out index for this project:
          index = self._index
  
          if index.obtain(requirement) is None:
              # Nothing is available.
              return None
  
          # Filter the available dists for the requirement and source flag
          dists = [dist for dist in index[requirement.project_name]
                   if ((dist in requirement)
                       and
                       ((not source) or
                        (dist.precedence == pkg_resources.SOURCE_DIST)
                        )
                       )
                   ]
  
          # If we prefer final dists, filter for final and use the
          # result if it is non empty.
          if self._prefer_final:
              fdists = [dist for dist in dists
                        if _final_version(dist.parsed_version)
                        ]
              if fdists:
                  # There are final dists, so only use those
                  dists = fdists
  
          # Now find the best one:
          best = []
          bestv = ()
          for dist in dists:
              distv = dist.parsed_version
              if distv > bestv:
                  best = [dist]
                  bestv = distv
              elif distv == bestv:
                  best.append(dist)
  
          if not best:
              return None
  
          if len(best) == 1:
              return best[0]
  
          if self._download_cache:
              for dist in best:
                  if (realpath(os.path.dirname(dist.location))
                      ==
                      self._download_cache
                      ):
                      return dist
  
          best.sort()
          return best[-1]
  
      def _fetch(self, dist, tmp, download_cache):
          if (download_cache
              and (realpath(os.path.dirname(dist.location)) == download_cache)
              ):
              return dist
  
          new_location = self._index.download(dist.location, tmp)
          if (download_cache
              and (realpath(new_location) == realpath(dist.location))
              and os.path.isfile(new_location)
              ):
              # setuptools avoids making extra copies, but we want to copy
              # to the download cache
              shutil.copy2(new_location, tmp)
              new_location = os.path.join(tmp, os.path.basename(new_location))
  
          return dist.clone(location=new_location)
  
      def _get_dist(self, requirement, ws):
  
          __doing__ = 'Getting distribution for %r.', str(requirement)
  
          # Maybe an existing dist is already the best dist that satisfies the
          # requirement
          dist, avail = self._satisfied(requirement)
  
          if dist is None:
              if self._dest is None:
                  raise zc.buildout.UserError(
                      "We don't have a distribution for %s\n"
                      "and can't install one in offline (no-install) mode.\n"
                      % requirement)
  
              logger.info(*__doing__)
  
              # Retrieve the dist:
              if avail is None:
                  self._index.obtain(requirement)
                  raise MissingDistribution(requirement, ws)
  
              # We may overwrite distributions, so clear importer
              # cache.
              sys.path_importer_cache.clear()
  
              tmp = self._download_cache
              if tmp is None:
                  tmp = tempfile.mkdtemp('get_dist')
  
              try:
                  dist = self._fetch(avail, tmp, self._download_cache)
  
                  if dist is None:
                      raise zc.buildout.UserError(
                          "Couln't download distribution %s." % avail)
  
                  if dist.precedence == pkg_resources.EGG_DIST:
                      # It's already an egg, just fetch it into the dest
  
                      newloc = os.path.join(
                          self._dest, os.path.basename(dist.location))
  
                      if os.path.isdir(dist.location):
                          # we got a directory. It must have been
                          # obtained locally.  Just copy it.
                          shutil.copytree(dist.location, newloc)
                      else:
  
  
                          setuptools.archive_util.unpack_archive(
                              dist.location, newloc)
  
                      redo_pyc(newloc)
  
                      # Getting the dist from the environment causes the
                      # distribution meta data to be read.  Cloning isn't
                      # good enough.
                      dists = pkg_resources.Environment([newloc])[
                          dist.project_name]
                  else:
                      # It's some other kind of dist.  We'll let easy_install
                      # deal with it:
                      dists = self._call_easy_install(
                          dist.location, ws, self._dest, dist)
                      for dist in dists:
                          redo_pyc(dist.location)
  
              finally:
                  if tmp != self._download_cache:
                      shutil.rmtree(tmp)
  
              self._env.scan([self._dest])
              dist = self._env.best_match(requirement, ws)
              logger.info("Got %s.", dist)
  
          else:
              dists = [dist]
  
          for dist in dists:
              if (dist.has_metadata('dependency_links.txt')
                  and not self._install_from_cache
                  and self._use_dependency_links
                  ):
                  for link in dist.get_metadata_lines('dependency_links.txt'):
                      link = link.strip()
                      if link not in self._links:
                          logger.debug('Adding find link %r from %s', link, dist)
                          self._links.append(link)
                          self._index = _get_index(self._index_url, self._links,
                                                   self._allow_hosts)
  
          for dist in dists:
              # Check whether we picked a version and, if we did, report it:
              if not (
                  dist.precedence == pkg_resources.DEVELOP_DIST
                  or
                  (len(requirement.specs) == 1
                   and
                   requirement.specs[0][0] == '==')
                  ):
                  logger.debug('Picked: %s = %s',
                               dist.project_name, dist.version)
                  self._picked_versions[dist.project_name] = dist.version
  
                  if not self._allow_picked_versions:
                      raise zc.buildout.UserError(
                          'Picked: %s = %s' % (dist.project_name, dist.version)
                          )
  
          return dists
  
      def _maybe_add_setuptools(self, ws, dist):
          if dist.has_metadata('namespace_packages.txt'):
              for r in dist.requires():
                  if r.project_name in ('setuptools', 'setuptools'):
                      break
              else:
                  # We have a namespace package but no requirement for setuptools
                  if dist.precedence == pkg_resources.DEVELOP_DIST:
                      logger.warn(
                          "Develop distribution: %s\n"
                          "uses namespace packages but the distribution "
                          "does not require setuptools.",
                          dist)
                  requirement = self._constrain(
                      pkg_resources.Requirement.parse('setuptools')
                      )
                  if ws.find(requirement) is None:
                      for dist in self._get_dist(requirement, ws):
                          ws.add(dist)
  
  
      def _constrain(self, requirement):
          constraint = self._versions.get(requirement.project_name.lower())
          if constraint:
              requirement = _constrained_requirement(constraint, requirement)
          return requirement
  
      def install(self, specs, working_set=None):
  
          logger.debug('Installing %s.', repr(specs)[1:-1])
  
          path = self._path
          dest = self._dest
          if dest is not None and dest not in path:
              path.insert(0, dest)
  
          requirements = [self._constrain(pkg_resources.Requirement.parse(spec))
                          for spec in specs]
  
  
  
          if working_set is None:
              ws = pkg_resources.WorkingSet([])
          else:
              ws = working_set
  
          for requirement in requirements:
              for dist in self._get_dist(requirement, ws):
                  ws.add(dist)
                  self._maybe_add_setuptools(ws, dist)
  
          # OK, we have the requested distributions and they're in the working
          # set, but they may have unmet requirements.  We'll simply keep
          # trying to resolve requirements, adding missing requirements as they
          # are reported.
          #
          # Note that we don't pass in the environment, because we want
          # to look for new eggs unless what we have is the best that
          # matches the requirement.
          while 1:
              try:
                  ws.resolve(requirements)
              except pkg_resources.DistributionNotFound:
                  err = sys.exc_info()[1]
                  [requirement] = err.args
                  requirement = self._constrain(requirement)
                  if dest:
                      logger.debug('Getting required %r', str(requirement))
                  else:
                      logger.debug('Adding required %r', str(requirement))
                  _log_requirement(ws, requirement)
  
                  for dist in self._get_dist(requirement, ws):
                      ws.add(dist)
                      self._maybe_add_setuptools(ws, dist)
              except pkg_resources.VersionConflict:
                  err = sys.exc_info()[1]
                  raise VersionConflict(err, ws)
              else:
                  break
  
          return ws
  
      def build(self, spec, build_ext):
  
          requirement = self._constrain(pkg_resources.Requirement.parse(spec))
  
          dist, avail = self._satisfied(requirement, 1)
          if dist is not None:
              return [dist.location]
  
          # Retrieve the dist:
          if avail is None:
              raise zc.buildout.UserError(
                  "Couldn't find a source distribution for %r."
                  % str(requirement))
  
          if self._dest is None:
              raise zc.buildout.UserError(
                  "We don't have a distribution for %s\n"
                  "and can't build one in offline (no-install) mode.\n"
                  % requirement
                  )
  
          logger.debug('Building %r', spec)
  
          tmp = self._download_cache
          if tmp is None:
              tmp = tempfile.mkdtemp('get_dist')
  
          try:
              dist = self._fetch(avail, tmp, self._download_cache)
  
              build_tmp = tempfile.mkdtemp('build')
              try:
                  setuptools.archive_util.unpack_archive(dist.location,
                                                         build_tmp)
                  if os.path.exists(os.path.join(build_tmp, 'setup.py')):
                      base = build_tmp
                  else:
                      setups = glob.glob(
                          os.path.join(build_tmp, '*', 'setup.py'))
                      if not setups:
                          raise distutils.errors.DistutilsError(
                              "Couldn't find a setup script in %s"
                              % os.path.basename(dist.location)
                              )
                      if len(setups) > 1:
                          raise distutils.errors.DistutilsError(
                              "Multiple setup scripts in %s"
                              % os.path.basename(dist.location)
                              )
                      base = os.path.dirname(setups[0])
  
                  setup_cfg = os.path.join(base, 'setup.cfg')
                  if not os.path.exists(setup_cfg):
                      f = open(setup_cfg, 'w')
                      f.close()
                  setuptools.command.setopt.edit_config(
                      setup_cfg, dict(build_ext=build_ext))
  
                  dists = self._call_easy_install(
                      base, pkg_resources.WorkingSet(),
                      self._dest, dist)
  
                  for dist in dists:
                      redo_pyc(dist.location)
  
                  return [dist.location for dist in dists]
              finally:
                  shutil.rmtree(build_tmp)
  
          finally:
              if tmp != self._download_cache:
                  shutil.rmtree(tmp)
  
  
  def normalize_versions(versions):
      """Return version dict with keys normalized to lowercase.
  
      PyPI is case-insensitive and not all distributions are consistent in
      their own naming.
      """
      return dict([(k.lower(), v) for (k, v) in versions.items()])
  
  
  def default_versions(versions=None):
      old = Installer._versions
      if versions is not None:
          Installer._versions = normalize_versions(versions)
      return old
  
  def download_cache(path=-1):
      old = Installer._download_cache
      if path != -1:
          if path:
              path = realpath(path)
          Installer._download_cache = path
      return old
  
  def install_from_cache(setting=None):
      old = Installer._install_from_cache
      if setting is not None:
          Installer._install_from_cache = bool(setting)
      return old
  
  def prefer_final(setting=None):
      old = Installer._prefer_final
      if setting is not None:
          Installer._prefer_final = bool(setting)
      return old
  
  def use_dependency_links(setting=None):
      old = Installer._use_dependency_links
      if setting is not None:
          Installer._use_dependency_links = bool(setting)
      return old
  
  def allow_picked_versions(setting=None):
      old = Installer._allow_picked_versions
      if setting is not None:
          Installer._allow_picked_versions = bool(setting)
      return old
  
  def store_required_by(setting=None):
      old = Installer._store_required_by
      if setting is not None:
          Installer._store_required_by = bool(setting)
      return old
  
  def get_picked_versions():
      picked_versions = sorted(Installer._picked_versions.items())
      required_by = Installer._required_by
      return (picked_versions, required_by)
  
  
  def install(specs, dest,
              links=(), index=None,
              executable=sys.executable,
              always_unzip=None, # Backward compat :/
              path=None, working_set=None, newest=True, versions=None,
              use_dependency_links=None, allow_hosts=('*',),
              include_site_packages=None,
              allowed_eggs_from_site_packages=None,
              ):
      assert executable == sys.executable, (executable, sys.executable)
      assert include_site_packages is None
      assert allowed_eggs_from_site_packages is None
  
      installer = Installer(dest, links, index, sys.executable,
                            always_unzip, path,
                            newest, versions, use_dependency_links,
                            allow_hosts=allow_hosts)
      return installer.install(specs, working_set)
  
  
  def build(spec, dest, build_ext,
            links=(), index=None,
            executable=sys.executable,
            path=None, newest=True, versions=None, allow_hosts=('*',)):
      assert executable == sys.executable, (executable, sys.executable)
      installer = Installer(dest, links, index, executable,
                            True, path, newest,
                            versions, allow_hosts=allow_hosts)
      return installer.build(spec, build_ext)
  
  
  
  def _rm(*paths):
      for path in paths:
          if os.path.isdir(path):
              shutil.rmtree(path)
          elif os.path.exists(path):
              os.remove(path)
  
  def _copyeggs(src, dest, suffix, undo):
      result = []
      undo.append(lambda : _rm(*result))
      for name in os.listdir(src):
          if name.endswith(suffix):
              new = os.path.join(dest, name)
              _rm(new)
              os.rename(os.path.join(src, name), new)
              result.append(new)
  
      assert len(result) == 1, str(result)
      undo.pop()
  
      return result[0]
  
  def develop(setup, dest,
              build_ext=None,
              executable=sys.executable):
      assert executable == sys.executable, (executable, sys.executable)
      if os.path.isdir(setup):
          directory = setup
          setup = os.path.join(directory, 'setup.py')
      else:
          directory = os.path.dirname(setup)
  
      undo = []
      try:
          if build_ext:
              setup_cfg = os.path.join(directory, 'setup.cfg')
              if os.path.exists(setup_cfg):
                  os.rename(setup_cfg, setup_cfg+'-develop-aside')
                  def restore_old_setup():
                      if os.path.exists(setup_cfg):
                          os.remove(setup_cfg)
                      os.rename(setup_cfg+'-develop-aside', setup_cfg)
                  undo.append(restore_old_setup)
              else:
                  f = open(setup_cfg, 'w')
                  f.close()
                  undo.append(lambda: os.remove(setup_cfg))
              setuptools.command.setopt.edit_config(
                  setup_cfg, dict(build_ext=build_ext))
  
          fd, tsetup = tempfile.mkstemp()
          undo.append(lambda: os.remove(tsetup))
          undo.append(lambda: os.close(fd))
  
          os.write(fd, (runsetup_template % dict(
              setuptools=setuptools_loc,
              setupdir=directory,
              setup=setup,
              __file__ = setup,
              )).encode())
  
          tmp3 = tempfile.mkdtemp('build', dir=dest)
          undo.append(lambda : shutil.rmtree(tmp3))
  
          args = [executable,  tsetup, '-q', 'develop', '-mxN', '-d', tmp3]
  
          log_level = logger.getEffectiveLevel()
          if log_level <= 0:
              if log_level == 0:
                  del args[2]
              else:
                  args[2] == '-v'
          if log_level < logging.DEBUG:
              logger.debug("in: %r\n%s", directory, ' '.join(args))
  
          call_subprocess(args)
  
          return _copyeggs(tmp3, dest, '.egg-link', undo)
  
      finally:
          undo.reverse()
          [f() for f in undo]
  
  
  def working_set(specs, executable, path=None,
                  include_site_packages=None,
                  allowed_eggs_from_site_packages=None):
      # Backward compat:
      if path is None:
          path = executable
      else:
          assert executable == sys.executable, (executable, sys.executable)
      assert include_site_packages is None
      assert allowed_eggs_from_site_packages is None
  
      return install(specs, None, path=path)
  
  def scripts(reqs, working_set, executable, dest=None,
              scripts=None,
              extra_paths=(),
              arguments='',
              interpreter=None,
              initialization='',
              relative_paths=False,
              ):
      assert executable == sys.executable, (executable, sys.executable)
  
      path = [dist.location for dist in working_set]
      path.extend(extra_paths)
      # order preserving unique
      unique_path = []
      for p in path:
          if p not in unique_path:
              unique_path.append(p)
      path = list(map(realpath, unique_path))
  
      generated = []
  
      if isinstance(reqs, str):
          raise TypeError('Expected iterable of requirements or entry points,'
                          ' got string.')
  
      if initialization:
          initialization = '\n'+initialization+'\n'
  
      entry_points = []
      distutils_scripts = []
      for req in reqs:
          if isinstance(req, str):
              req = pkg_resources.Requirement.parse(req)
              dist = working_set.find(req)
              # regular console_scripts entry points
              for name in pkg_resources.get_entry_map(dist, 'console_scripts'):
                  entry_point = dist.get_entry_info('console_scripts', name)
                  entry_points.append(
                      (name, entry_point.module_name,
                       '.'.join(entry_point.attrs))
                      )
              # The metadata on "old-style" distutils scripts is not retained by
              # distutils/setuptools, except by placing the original scripts in
              # /EGG-INFO/scripts/.
              if dist.metadata_isdir('scripts'):
                  for name in dist.metadata_listdir('scripts'):
                      if dist.metadata_isdir('scripts/' + name):
                          # Probably Python 3 __pycache__ directory.
                          continue
                      contents = dist.get_metadata('scripts/' + name)
                      distutils_scripts.append((name, contents))
          else:
              entry_points.append(req)
  
      for name, module_name, attrs in entry_points:
          if scripts is not None:
              sname = scripts.get(name)
              if sname is None:
                  continue
          else:
              sname = name
  
          sname = os.path.join(dest, sname)
          spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)
  
          generated.extend(
              _script(module_name, attrs, spath, sname, arguments,
                      initialization, rpsetup)
              )
  
      for name, contents in distutils_scripts:
          if scripts is not None:
              sname = scripts.get(name)
              if sname is None:
                  continue
          else:
              sname = name
  
          sname = os.path.join(dest, sname)
          spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)
  
          generated.extend(
              _distutils_script(spath, sname, contents, initialization, rpsetup)
              )
  
      if interpreter:
          sname = os.path.join(dest, interpreter)
          spath, rpsetup = _relative_path_and_setup(sname, path, relative_paths)
          generated.extend(_pyscript(spath, sname, rpsetup, initialization))
  
      return generated
  
  
  def _relative_path_and_setup(sname, path, relative_paths):
      if relative_paths:
          relative_paths = os.path.normcase(relative_paths)
          sname = os.path.normcase(os.path.abspath(sname))
          spath = ',\n  '.join(
              [_relativitize(os.path.normcase(path_item), sname, relative_paths)
               for path_item in path]
              )
          rpsetup = relative_paths_setup
          for i in range(_relative_depth(relative_paths, sname)):
              rpsetup += "base = os.path.dirname(base)\n"
      else:
          spath = repr(path)[1:-1].replace(', ', ',\n  ')
          rpsetup = ''
      return spath, rpsetup
  
  
  def _relative_depth(common, path):
      n = 0
      while 1:
          dirname = os.path.dirname(path)
          if dirname == path:
              raise AssertionError("dirname of %s is the same" % dirname)
          if dirname == common:
              break
          n += 1
          path = dirname
      return n
  
  
  def _relative_path(common, path):
      r = []
      while 1:
          dirname, basename = os.path.split(path)
          r.append(basename)
          if dirname == common:
              break
          if dirname == path:
              raise AssertionError("dirname of %s is the same" % dirname)
          path = dirname
      r.reverse()
      return os.path.join(*r)
  
  
  def _relativitize(path, script, relative_paths):
      if path == script:
          raise AssertionError("path == script")
      common = os.path.dirname(os.path.commonprefix([path, script]))
      if (common == relative_paths or
          common.startswith(os.path.join(relative_paths, ''))
          ):
          return "join(base, %r)" % _relative_path(common, path)
      else:
          return repr(path)
  
  
  relative_paths_setup = """
  import os
  
  join = os.path.join
  base = os.path.dirname(os.path.abspath(os.path.realpath(__file__)))
  """
  
  def _script(module_name, attrs, path, dest, arguments, initialization, rsetup):
      if is_win32:
          dest += '-script.py'
  
      python = _safe_arg(sys.executable)
  
      contents = script_template % dict(
          python = python,
          path = path,
          module_name = module_name,
          attrs = attrs,
          arguments = arguments,
          initialization = initialization,
          relative_paths_setup = rsetup,
          )
      return _create_script(contents, dest)
  
  
  def _distutils_script(path, dest, script_content, initialization, rsetup):
      if is_win32:
          dest += '-script.py'
  
      lines = script_content.splitlines(True)
      if not ('#!' in lines[0]) and ('python' in lines[0]):
          # The script doesn't follow distutil's rules.  Ignore it.
          return []
      lines = lines[1:]  # Strip off the first hashbang line.
      line_with_first_import = len(lines)
      for line_number, line in enumerate(lines):
          if not 'import' in line:
              continue
          if not (line.startswith('import') or line.startswith('from')):
              continue
          if '__future__' in line:
              continue
          line_with_first_import = line_number
          break
  
      before = ''.join(lines[:line_with_first_import])
      after = ''.join(lines[line_with_first_import:])
  
      python = _safe_arg(sys.executable)
  
      contents = distutils_script_template % dict(
          python = python,
          path = path,
          initialization = initialization,
          relative_paths_setup = rsetup,
          before = before,
          after = after
          )
      return _create_script(contents, dest)
  
  def _file_changed(filename, old_contents, mode='r'):
      try:
          with open(filename, mode) as f:
              return f.read() != old_contents
      except EnvironmentError as e:
          if e.errno == errno.ENOENT:
              return True
          else:
              raise
  
  def _create_script(contents, dest):
      generated = []
      script = dest
  
      changed = _file_changed(dest, contents)
  
      if is_win32:
          # generate exe file and give the script a magic name:
          win32_exe = os.path.splitext(dest)[0] # remove ".py"
          if win32_exe.endswith('-script'):
              win32_exe = win32_exe[:-7] # remove "-script"
          win32_exe = win32_exe + '.exe' # add ".exe"
          try:
              new_data = setuptools.command.easy_install.get_win_launcher('cli')
          except AttributeError:
              # fall back for compatibility with older Distribute versions
              new_data = pkg_resources.resource_string('setuptools', 'cli.exe')
  
          if _file_changed(win32_exe, new_data, 'rb'):
              # Only write it if it's different.
              with open(win32_exe, 'wb') as f:
                  f.write(new_data)
          generated.append(win32_exe)
  
      if changed:
          with open(dest, 'w') as f:
              f.write(contents)
          logger.info(
              "Generated script %r.",
              # Normalize for windows
              script.endswith('-script.py') and script[:-10] or script)
  
          try:
              os.chmod(dest, _execute_permission())
          except (AttributeError, os.error):
              pass
  
      generated.append(dest)
      return generated
  
  
  if is_jython and jython_os_name == 'linux':
      script_header = '#!/usr/bin/env %(python)s'
  else:
      script_header = '#!%(python)s'
  
  
  script_template = script_header + '''\
  
  %(relative_paths_setup)s
  import sys
  sys.path[0:0] = [
    %(path)s,
    ]
  %(initialization)s
  import %(module_name)s
  
  if __name__ == '__main__':
      sys.exit(%(module_name)s.%(attrs)s(%(arguments)s))
  '''
  
  distutils_script_template = script_header + '''
  %(before)s
  %(relative_paths_setup)s
  import sys
  sys.path[0:0] = [
    %(path)s,
    ]
  %(initialization)s
  
  %(after)s'''
  
  
  def _pyscript(path, dest, rsetup, initialization=''):
      generated = []
      script = dest
      if is_win32:
          dest += '-script.py'
  
      python = _safe_arg(sys.executable)
      if path:
          path += ','  # Courtesy comma at the end of the list.
  
      contents = py_script_template % dict(
          python = python,
          path = path,
          relative_paths_setup = rsetup,
          initialization=initialization,
          )
      changed = _file_changed(dest, contents)
  
      if is_win32:
          # generate exe file and give the script a magic name:
          exe = script + '.exe'
          with open(exe, 'wb') as f:
              f.write(
                  pkg_resources.resource_string('setuptools', 'cli.exe')
              )
          generated.append(exe)
  
      if changed:
          with open(dest, 'w') as f:
              f.write(contents)
          try:
              os.chmod(dest, _execute_permission())
          except (AttributeError, os.error):
              pass
          logger.info("Generated interpreter %r.", script)
  
      generated.append(dest)
      return generated
  
  py_script_template = script_header + '''\
  
  %(relative_paths_setup)s
  import sys
  
  sys.path[0:0] = [
    %(path)s
    ]
  %(initialization)s
  
  _interactive = True
  if len(sys.argv) > 1:
      _options, _args = __import__("getopt").getopt(sys.argv[1:], 'ic:m:')
      _interactive = False
      for (_opt, _val) in _options:
          if _opt == '-i':
              _interactive = True
          elif _opt == '-c':
              exec(_val)
          elif _opt == '-m':
              sys.argv[1:] = _args
              _args = []
              __import__("runpy").run_module(
                   _val, {}, "__main__", alter_sys=True)
  
      if _args:
          sys.argv[:] = _args
          __file__ = _args[0]
          del _options, _args
          with open(__file__, 'U') as __file__f:
              exec(compile(__file__f.read(), __file__, "exec"))
  
  if _interactive:
      del _interactive
      __import__("code").interact(banner="", local=globals())
  '''
  
  runsetup_template = """
  import sys
  sys.path.insert(0, %(setupdir)r)
  sys.path.insert(0, %(setuptools)r)
  
  import os, setuptools
  
  __file__ = %(__file__)r
  
  os.chdir(%(setupdir)r)
  sys.argv[0] = %(setup)r
  
  with open(%(setup)r, 'U') as f:
      exec(compile(f.read(), %(setup)r, 'exec'))
  """
  
  
  class VersionConflict(zc.buildout.UserError):
  
      def __init__(self, err, ws):
          ws = list(ws)
          ws.sort()
          self.err, self.ws = err, ws
  
      def __str__(self):
          existing_dist, req = self.err.args
          result = ["There is a version conflict.",
                    "We already have: %s" % existing_dist,
                    ]
          for dist in self.ws:
              if req in dist.requires():
                  result.append("but %s requires %r." % (dist, str(req)))
          return '\n'.join(result)
  
  
  class MissingDistribution(zc.buildout.UserError):
  
      def __init__(self, req, ws):
          ws = list(ws)
          ws.sort()
          self.data = req, ws
  
      def __str__(self):
          req, ws = self.data
          return "Couldn't find a distribution for %r." % str(req)
  
  def _log_requirement(ws, req):
      if (not logger.isEnabledFor(logging.DEBUG) and
          not Installer._store_required_by):
          # Sorting the working set and iterating over it's requirements
          # is expensive, so short circuit the work if it won't even be
          # logged.  When profiling a simple buildout with 10 parts with
          # identical and large working sets, this resulted in a
          # decrease of run time from 93.411 to 15.068 seconds, about a
          # 6 fold improvement.
          return
  
      ws = list(ws)
      ws.sort()
      for dist in ws:
          if req in dist.requires():
              logger.debug("  required by %s." % dist)
              req_ = str(req)
              if req_ not in Installer._required_by:
                  Installer._required_by[req_] = set()
              Installer._required_by[req_].add(str(dist.as_requirement()))
  
  def _fix_file_links(links):
      for link in links:
          if link.startswith('file://') and link[-1] != '/':
              if os.path.isdir(link[7:]):
                  # work around excessive restriction in setuptools:
                  link += '/'
          yield link
  
  _final_parts = '*final-', '*final'
  def _final_version(parsed_version):
      for part in parsed_version:
          if (part[:1] == '*') and (part not in _final_parts):
              return False
      return True
  
  def redo_pyc(egg):
      if not os.path.isdir(egg):
          return
      for dirpath, dirnames, filenames in os.walk(egg):
          for filename in filenames:
              if not filename.endswith('.py'):
                  continue
              filepath = os.path.join(dirpath, filename)
              if not (os.path.exists(filepath+'c')
                      or os.path.exists(filepath+'o')):
                  # If it wasn't compiled, it may not be compilable
                  continue
  
              # OK, it looks like we should try to compile.
  
              # Remove old files.
              for suffix in 'co':
                  if os.path.exists(filepath+suffix):
                      os.remove(filepath+suffix)
  
              # Compile under current optimization
              try:
                  py_compile.compile(filepath)
              except py_compile.PyCompileError:
                  logger.warning("Couldn't compile %s", filepath)
              else:
                  # Recompile under other optimization. :)
                  args = [sys.executable]
                  if __debug__:
                      args.append('-O')
                  args.extend(['-m', 'py_compile', filepath])
  
                  call_subprocess(args)
  
  def _constrained_requirement(constraint, requirement):
      return pkg_resources.Requirement.parse(
          "%s[%s]%s" % (
              requirement.project_name,
              ','.join(requirement.extras),
              _constrained_requirement_constraint(constraint, requirement)
              )
          )
  
  class IncompatibleConstraintError(zc.buildout.UserError):
      """A specified version is incompatible with a given requirement.
      """
  
  IncompatibleVersionError = IncompatibleConstraintError # Backward compatibility
  
  def bad_constraint(constraint, requirement):
      logger.error("The constraint, %s, is not consistent with the "
                   "requirement, %r.", constraint, str(requirement))
      raise IncompatibleConstraintError("Bad constraint", constraint, requirement)
  
  _parse_constraint = re.compile(r'([<>]=?)\s*(\S+)').match
  _comparef = {
      '>' : lambda x, y: x >  y,
      '>=': lambda x, y: x >= y,
      '<' : lambda x, y: x <  y,
      '<=': lambda x, y: x <= y,
      }
  _opop = {'<': '>', '>': '<'}
  _opeqop = {'<': '>=', '>': '<='}
  def _constrained_requirement_constraint(constraint, requirement):
  
      # Simple cases:
  
      # No specs to merge with:
      if not requirement.specs:
          if not constraint[0] in '<=>':
              constraint = '==' + constraint
          return constraint
  
      # Simple single-version constraint:
      if constraint[0] not in '<>':
          if constraint.startswith('='):
              assert constraint.startswith('==')
              constraint = constraint[2:]
          if constraint in requirement:
              return '=='+constraint
          bad_constraint(constraint, requirement)
  
  
      # OK, we have a complex constraint (<. <=, >=, or >) and specs.
      # In many cases, the spec needs to filter constraints.
      # In other cases, the constraints need to limit the constraint.
  
      specs = requirement.specs
      cop, cv = _parse_constraint(constraint).group(1, 2)
      pcv = pkg_resources.parse_version(cv)
  
      # Special case, all of the specs are == specs:
      if not [op for (op, v) in specs if op != '==']:
          # There aren't any non-== specs.
  
          # See if any of the specs satisfy the constraint:
          specs = [op+v for (op, v) in specs
                   if _comparef[cop](pkg_resources.parse_version(v), pcv)]
          if specs:
              return ','.join(specs)
  
          bad_constraint(constraint, requirement)
  
      cop0 = cop[0]
  
      # Normalize specs by splitting >= and <= specs. We need to do this
      # because these have really weird semantics. Also cache parsed
      # versions, which we'll need for comparisons:
      specs = []
      for op, v in requirement.specs:
          pv = pkg_resources.parse_version(v)
          if op == _opeqop[cop0]:
              specs.append((op[0], v, pv))
              specs.append(('==', v, pv))
          else:
              specs.append((op, v, pv))
  
      # Error if there are opposite specs that conflict with the constraint
      # and there are no equal specs that satisfy the constraint:
      if [v for (op, v, pv) in specs
          if op == _opop[cop0] and _comparef[_opop[cop0]](pv, pcv)
          ]:
          eqspecs = [op+v for (op, v, pv) in specs
                     if _comparef[cop](pv, pcv)]
          if eqspecs:
              # OK, we do, use these:
              return ','.join(eqspecs)
  
          bad_constraint(constraint, requirement)
  
      # We have a combination of range constraints and eq specs that
      # satisfy the requirement.
  
      # Return the constraint + the filtered specs
      return ','.join(
          op+v
          for (op, v) in (
              [(cop, cv)] +
              [(op, v) for (op, v, pv) in specs if _comparef[cop](pv, pcv)]
              )
          )
  