add --egg option to opt out --single-version-externally-managed

pip/commands/install.py

@@ -165,6 +165,12 @@ def __init__(self):
             action='store_true',
             help='Install to user-site')
 
+        self.parser.add_option(
+            '--egg',
+            dest='as_egg',
+            action='store_true',
+            help="Install as self contained egg file, like easy_install does.")
+
     def _build_package_finder(self, options, index_urls):
         """
         Create a package finder appropriate to this install command.
@@ -206,6 +212,7 @@ def run(self, options, args):
             download_dir=options.download_dir,
             download_cache=options.download_cache,
             upgrade=options.upgrade,
+            as_egg=options.as_egg,
             ignore_installed=options.ignore_installed,
             ignore_dependencies=options.ignore_dependencies,
             force_reinstall=options.force_reinstall)

pip/req.py

@@ -35,7 +35,7 @@
 class InstallRequirement(object):
 
     def __init__(self, req, comes_from, source_dir=None, editable=False,
-                 url=None, update=True):
+                 url=None, as_egg=False, update=True):
         self.extras = ()
         if isinstance(req, string_types):
             req = pkg_resources.Requirement.parse(req)
@@ -45,6 +45,7 @@ def __init__(self, req, comes_from, source_dir=None, editable=False,
         self.source_dir = source_dir
         self.editable = editable
         self.url = url
+        self.as_egg = as_egg
         self._egg_info_path = None
         # This holds the pkg_resources.Distribution object if this requirement
         # is already available:
@@ -556,6 +557,7 @@ def install(self, install_options, global_options=()):
         if self.editable:
             self.install_editable(install_options, global_options)
             return
+
         temp_location = tempfile.mkdtemp('-record', 'pip-')
         record_filename = os.path.join(temp_location, 'install-record.txt')
         try:
@@ -565,9 +567,11 @@ def install(self, install_options, global_options=()):
                 "exec(compile(open(__file__).read().replace('\\r\\n', '\\n'), __file__, 'exec'))" % self.setup_py] +\
                 list(global_options) + [
                 'install',
-                '--single-version-externally-managed',
                 '--record', record_filename]
 
+            if not self.as_egg:
+                install_args += ['--single-version-externally-managed']
+
             if running_under_virtualenv():
                 ## FIXME: I'm not sure if this is a reasonable location; probably not
                 ## but we can't put it in the default location, as that is a virtualenv symlink that isn't writable
@@ -781,7 +785,7 @@ def __repr__(self):
 class RequirementSet(object):
 
     def __init__(self, build_dir, src_dir, download_dir, download_cache=None,
-                 upgrade=False, ignore_installed=False,
+                 upgrade=False, ignore_installed=False, as_egg=False,
                  ignore_dependencies=False, force_reinstall=False):
         self.build_dir = build_dir
         self.src_dir = src_dir
@@ -798,6 +802,7 @@ def __init__(self, build_dir, src_dir, download_dir, download_cache=None,
         self.successfully_downloaded = []
         self.successfully_installed = []
         self.reqs_to_cleanup = []
+        self.as_egg = as_egg
 
     def __str__(self):
         reqs = [req for req in self.requirements.values()
@@ -807,6 +812,7 @@ def __str__(self):
 
     def add_requirement(self, install_req):
         name = install_req.name
+        install_req.as_egg = self.as_egg
         if not name:
             self.unnamed_requirements.append(install_req)
         else: