Update vendoring technique to match that used for packaging. Ref #229.

34 files changed, 1036 insertions, 68 deletions

diff --git a/Makefile b/Makefile
index 37dd26eb..54dad480 100644
--- a/Makefile
+++ b/Makefile
@@ -3,5 +3,9 @@ empty:
 
 update-vendored:
 	rm -rf pkg_resources/_vendor/packaging
-	pip install -r pkg_resources/_vendor/vendored.txt -t pkg_resources/_vendor/
+	python3.5 -m pip install -r pkg_resources/_vendor/vendored.txt -t pkg_resources/_vendor/
 	rm -rf pkg_resources/_vendor/*.{egg,dist}-info
+
+	rm -rf setuptools/_vendor/six
+	python3.5 -m pip install -r setuptools/_vendor/vendored.txt -t setuptools/_vendor/
+	rm -rf setuptools/_vendor/*.{egg,dist}-info
diff --git a/pkg_resources/tests/test_resources.py b/pkg_resources/tests/test_resources.py
index 92d0e49c..9fda892f 100644
--- a/pkg_resources/tests/test_resources.py
+++ b/pkg_resources/tests/test_resources.py
@@ -14,8 +14,6 @@ from pkg_resources import (parse_requirements, VersionConflict, parse_version,
 packaging = pkg_resources.packaging
 
 
-import six
-
 def safe_repr(obj, short=False):
     """ copied from Python2.7"""
     try:
@@ -315,7 +313,7 @@ class TestEntryPoints:
 
     def checkSubMap(self, m):
         assert len(m) == len(self.submap_expect)
-        for key, ep in six.iteritems(self.submap_expect):
+        for key, ep in self.submap_expect.items():
             assert repr(m.get(key)) == repr(ep)
 
     submap_expect = dict(
diff --git a/setup.py b/setup.py
index a21e5025..dfb578a1 100755
--- a/setup.py
+++ b/setup.py
@@ -148,9 +148,6 @@ setup_params = dict(
         Topic :: System :: Systems Administration
         Topic :: Utilities
         """).strip().splitlines(),
-    install_requires=[
-        'six>=1.5',
-    ],
     extras_require={
         "ssl:sys_platform=='win32'": "wincertstore==0.2",
         "certs": "certifi==2015.11.20",
diff --git a/setuptools/__init__.py b/setuptools/__init__.py
index fffcac76..6e1e5aa4 100644
--- a/setuptools/__init__.py
+++ b/setuptools/__init__.py
@@ -1,7 +1,5 @@
 """Extensions to the 'distutils' for large or complex distributions"""
 
-__import__('setuptools.bootstrap').bootstrap.ensure_deps()
-
 import os
 import functools
 import distutils.core
@@ -10,7 +8,12 @@ from distutils.core import Command as _Command
 from distutils.util import convert_path
 from fnmatch import fnmatchcase
 
-from six.moves import filterfalse
+try:
+    from setuptools._vendor.six.moves import filterfalse
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    from six.moves import filterfalse
 
 import setuptools.version
 from setuptools.extension import Extension
diff --git a/setuptools/_vendor/__init__.py b/setuptools/_vendor/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/setuptools/_vendor/__init__.py
diff --git a/setuptools/_vendor/six-1.7.3.egg b/setuptools/_vendor/six-1.7.3.egg
deleted file mode 100644
index fe3e82c6..00000000
--- a/setuptools/_vendor/six-1.7.3.egg
+++ /dev/null
diff --git a/setuptools/_vendor/six.py b/setuptools/_vendor/six.py
new file mode 100644
index 00000000..190c0239
--- /dev/null
+++ b/setuptools/_vendor/six.py
@@ -0,0 +1,868 @@
+"""Utilities for writing code that runs on Python 2 and 3"""
+
+# Copyright (c) 2010-2015 Benjamin Peterson
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import
+
+import functools
+import itertools
+import operator
+import sys
+import types
+
+__author__ = "Benjamin Peterson <benjamin@python.org>"
+__version__ = "1.10.0"
+
+
+# Useful for very coarse version differentiation.
+PY2 = sys.version_info[0] == 2
+PY3 = sys.version_info[0] == 3
+PY34 = sys.version_info[0:2] >= (3, 4)
+
+if PY3:
+    string_types = str,
+    integer_types = int,
+    class_types = type,
+    text_type = str
+    binary_type = bytes
+
+    MAXSIZE = sys.maxsize
+else:
+    string_types = basestring,
+    integer_types = (int, long)
+    class_types = (type, types.ClassType)
+    text_type = unicode
+    binary_type = str
+
+    if sys.platform.startswith("java"):
+        # Jython always uses 32 bits.
+        MAXSIZE = int((1 << 31) - 1)
+    else:
+        # It's possible to have sizeof(long) != sizeof(Py_ssize_t).
+        class X(object):
+
+            def __len__(self):
+                return 1 << 31
+        try:
+            len(X())
+        except OverflowError:
+            # 32-bit
+            MAXSIZE = int((1 << 31) - 1)
+        else:
+            # 64-bit
+            MAXSIZE = int((1 << 63) - 1)
+        del X
+
+
+def _add_doc(func, doc):
+    """Add documentation to a function."""
+    func.__doc__ = doc
+
+
+def _import_module(name):
+    """Import module, returning the module after the last dot."""
+    __import__(name)
+    return sys.modules[name]
+
+
+class _LazyDescr(object):
+
+    def __init__(self, name):
+        self.name = name
+
+    def __get__(self, obj, tp):
+        result = self._resolve()
+        setattr(obj, self.name, result)  # Invokes __set__.
+        try:
+            # This is a bit ugly, but it avoids running this again by
+            # removing this descriptor.
+            delattr(obj.__class__, self.name)
+        except AttributeError:
+            pass
+        return result
+
+
+class MovedModule(_LazyDescr):
+
+    def __init__(self, name, old, new=None):
+        super(MovedModule, self).__init__(name)
+        if PY3:
+            if new is None:
+                new = name
+            self.mod = new
+        else:
+            self.mod = old
+
+    def _resolve(self):
+        return _import_module(self.mod)
+
+    def __getattr__(self, attr):
+        _module = self._resolve()
+        value = getattr(_module, attr)
+        setattr(self, attr, value)
+        return value
+
+
+class _LazyModule(types.ModuleType):
+
+    def __init__(self, name):
+        super(_LazyModule, self).__init__(name)
+        self.__doc__ = self.__class__.__doc__
+
+    def __dir__(self):
+        attrs = ["__doc__", "__name__"]
+        attrs += [attr.name for attr in self._moved_attributes]
+        return attrs
+
+    # Subclasses should override this
+    _moved_attributes = []
+
+
+class MovedAttribute(_LazyDescr):
+
+    def __init__(self, name, old_mod, new_mod, old_attr=None, new_attr=None):
+        super(MovedAttribute, self).__init__(name)
+        if PY3:
+            if new_mod is None:
+                new_mod = name
+            self.mod = new_mod
+            if new_attr is None:
+                if old_attr is None:
+                    new_attr = name
+                else:
+                    new_attr = old_attr
+            self.attr = new_attr
+        else:
+            self.mod = old_mod
+            if old_attr is None:
+                old_attr = name
+            self.attr = old_attr
+
+    def _resolve(self):
+        module = _import_module(self.mod)
+        return getattr(module, self.attr)
+
+
+class _SixMetaPathImporter(object):
+
+    """
+    A meta path importer to import six.moves and its submodules.
+
+    This class implements a PEP302 finder and loader. It should be compatible
+    with Python 2.5 and all existing versions of Python3
+    """
+
+    def __init__(self, six_module_name):
+        self.name = six_module_name
+        self.known_modules = {}
+
+    def _add_module(self, mod, *fullnames):
+        for fullname in fullnames:
+            self.known_modules[self.name + "." + fullname] = mod
+
+    def _get_module(self, fullname):
+        return self.known_modules[self.name + "." + fullname]
+
+    def find_module(self, fullname, path=None):
+        if fullname in self.known_modules:
+            return self
+        return None
+
+    def __get_module(self, fullname):
+        try:
+            return self.known_modules[fullname]
+        except KeyError:
+            raise ImportError("This loader does not know module " + fullname)
+
+    def load_module(self, fullname):
+        try:
+            # in case of a reload
+            return sys.modules[fullname]
+        except KeyError:
+            pass
+        mod = self.__get_module(fullname)
+        if isinstance(mod, MovedModule):
+            mod = mod._resolve()
+        else:
+            mod.__loader__ = self
+        sys.modules[fullname] = mod
+        return mod
+
+    def is_package(self, fullname):
+        """
+        Return true, if the named module is a package.
+
+        We need this method to get correct spec objects with
+        Python 3.4 (see PEP451)
+        """
+        return hasattr(self.__get_module(fullname), "__path__")
+
+    def get_code(self, fullname):
+        """Return None
+
+        Required, if is_package is implemented"""
+        self.__get_module(fullname)  # eventually raises ImportError
+        return None
+    get_source = get_code  # same as get_code
+
+_importer = _SixMetaPathImporter(__name__)
+
+
+class _MovedItems(_LazyModule):
+
+    """Lazy loading of moved objects"""
+    __path__ = []  # mark as package
+
+
+_moved_attributes = [
+    MovedAttribute("cStringIO", "cStringIO", "io", "StringIO"),
+    MovedAttribute("filter", "itertools", "builtins", "ifilter", "filter"),
+    MovedAttribute("filterfalse", "itertools", "itertools", "ifilterfalse", "filterfalse"),
+    MovedAttribute("input", "__builtin__", "builtins", "raw_input", "input"),
+    MovedAttribute("intern", "__builtin__", "sys"),
+    MovedAttribute("map", "itertools", "builtins", "imap", "map"),
+    MovedAttribute("getcwd", "os", "os", "getcwdu", "getcwd"),
+    MovedAttribute("getcwdb", "os", "os", "getcwd", "getcwdb"),
+    MovedAttribute("range", "__builtin__", "builtins", "xrange", "range"),
+    MovedAttribute("reload_module", "__builtin__", "importlib" if PY34 else "imp", "reload"),
+    MovedAttribute("reduce", "__builtin__", "functools"),
+    MovedAttribute("shlex_quote", "pipes", "shlex", "quote"),
+    MovedAttribute("StringIO", "StringIO", "io"),
+    MovedAttribute("UserDict", "UserDict", "collections"),
+    MovedAttribute("UserList", "UserList", "collections"),
+    MovedAttribute("UserString", "UserString", "collections"),
+    MovedAttribute("xrange", "__builtin__", "builtins", "xrange", "range"),
+    MovedAttribute("zip", "itertools", "builtins", "izip", "zip"),
+    MovedAttribute("zip_longest", "itertools", "itertools", "izip_longest", "zip_longest"),
+    MovedModule("builtins", "__builtin__"),
+    MovedModule("configparser", "ConfigParser"),
+    MovedModule("copyreg", "copy_reg"),
+    MovedModule("dbm_gnu", "gdbm", "dbm.gnu"),
+    MovedModule("_dummy_thread", "dummy_thread", "_dummy_thread"),
+    MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),
+    MovedModule("http_cookies", "Cookie", "http.cookies"),
+    MovedModule("html_entities", "htmlentitydefs", "html.entities"),
+    MovedModule("html_parser", "HTMLParser", "html.parser"),
+    MovedModule("http_client", "httplib", "http.client"),
+    MovedModule("email_mime_multipart", "email.MIMEMultipart", "email.mime.multipart"),
+    MovedModule("email_mime_nonmultipart", "email.MIMENonMultipart", "email.mime.nonmultipart"),
+    MovedModule("email_mime_text", "email.MIMEText", "email.mime.text"),
+    MovedModule("email_mime_base", "email.MIMEBase", "email.mime.base"),
+    MovedModule("BaseHTTPServer", "BaseHTTPServer", "http.server"),
+    MovedModule("CGIHTTPServer", "CGIHTTPServer", "http.server"),
+    MovedModule("SimpleHTTPServer", "SimpleHTTPServer", "http.server"),
+    MovedModule("cPickle", "cPickle", "pickle"),
+    MovedModule("queue", "Queue"),
+    MovedModule("reprlib", "repr"),
+    MovedModule("socketserver", "SocketServer"),
+    MovedModule("_thread", "thread", "_thread"),
+    MovedModule("tkinter", "Tkinter"),
+    MovedModule("tkinter_dialog", "Dialog", "tkinter.dialog"),
+    MovedModule("tkinter_filedialog", "FileDialog", "tkinter.filedialog"),
+    MovedModule("tkinter_scrolledtext", "ScrolledText", "tkinter.scrolledtext"),
+    MovedModule("tkinter_simpledialog", "SimpleDialog", "tkinter.simpledialog"),
+    MovedModule("tkinter_tix", "Tix", "tkinter.tix"),
+    MovedModule("tkinter_ttk", "ttk", "tkinter.ttk"),
+    MovedModule("tkinter_constants", "Tkconstants", "tkinter.constants"),
+    MovedModule("tkinter_dnd", "Tkdnd", "tkinter.dnd"),
+    MovedModule("tkinter_colorchooser", "tkColorChooser",
+                "tkinter.colorchooser"),
+    MovedModule("tkinter_commondialog", "tkCommonDialog",
+                "tkinter.commondialog"),
+    MovedModule("tkinter_tkfiledialog", "tkFileDialog", "tkinter.filedialog"),
+    MovedModule("tkinter_font", "tkFont", "tkinter.font"),
+    MovedModule("tkinter_messagebox", "tkMessageBox", "tkinter.messagebox"),
+    MovedModule("tkinter_tksimpledialog", "tkSimpleDialog",
+                "tkinter.simpledialog"),
+    MovedModule("urllib_parse", __name__ + ".moves.urllib_parse", "urllib.parse"),
+    MovedModule("urllib_error", __name__ + ".moves.urllib_error", "urllib.error"),
+    MovedModule("urllib", __name__ + ".moves.urllib", __name__ + ".moves.urllib"),
+    MovedModule("urllib_robotparser", "robotparser", "urllib.robotparser"),
+    MovedModule("xmlrpc_client", "xmlrpclib", "xmlrpc.client"),
+    MovedModule("xmlrpc_server", "SimpleXMLRPCServer", "xmlrpc.server"),
+]
+# Add windows specific modules.
+if sys.platform == "win32":
+    _moved_attributes += [
+        MovedModule("winreg", "_winreg"),
+    ]
+
+for attr in _moved_attributes:
+    setattr(_MovedItems, attr.name, attr)
+    if isinstance(attr, MovedModule):
+        _importer._add_module(attr, "moves." + attr.name)
+del attr
+
+_MovedItems._moved_attributes = _moved_attributes
+
+moves = _MovedItems(__name__ + ".moves")
+_importer._add_module(moves, "moves")
+
+
+class Module_six_moves_urllib_parse(_LazyModule):
+
+    """Lazy loading of moved objects in six.moves.urllib_parse"""
+
+
+_urllib_parse_moved_attributes = [
+    MovedAttribute("ParseResult", "urlparse", "urllib.parse"),
+    MovedAttribute("SplitResult", "urlparse", "urllib.parse"),
+    MovedAttribute("parse_qs", "urlparse", "urllib.parse"),
+    MovedAttribute("parse_qsl", "urlparse", "urllib.parse"),
+    MovedAttribute("urldefrag", "urlparse", "urllib.parse"),
+    MovedAttribute("urljoin", "urlparse", "urllib.parse"),
+    MovedAttribute("urlparse", "urlparse", "urllib.parse"),
+    MovedAttribute("urlsplit", "urlparse", "urllib.parse"),
+    MovedAttribute("urlunparse", "urlparse", "urllib.parse"),
+    MovedAttribute("urlunsplit", "urlparse", "urllib.parse"),
+    MovedAttribute("quote", "urllib", "urllib.parse"),
+    MovedAttribute("quote_plus", "urllib", "urllib.parse"),
+    MovedAttribute("unquote", "urllib", "urllib.parse"),
+    MovedAttribute("unquote_plus", "urllib", "urllib.parse"),
+    MovedAttribute("urlencode", "urllib", "urllib.parse"),
+    MovedAttribute("splitquery", "urllib", "urllib.parse"),
+    MovedAttribute("splittag", "urllib", "urllib.parse"),
+    MovedAttribute("splituser", "urllib", "urllib.parse"),
+    MovedAttribute("uses_fragment", "urlparse", "urllib.parse"),
+    MovedAttribute("uses_netloc", "urlparse", "urllib.parse"),
+    MovedAttribute("uses_params", "urlparse", "urllib.parse"),
+    MovedAttribute("uses_query", "urlparse", "urllib.parse"),
+    MovedAttribute("uses_relative", "urlparse", "urllib.parse"),
+]
+for attr in _urllib_parse_moved_attributes:
+    setattr(Module_six_moves_urllib_parse, attr.name, attr)
+del attr
+
+Module_six_moves_urllib_parse._moved_attributes = _urllib_parse_moved_attributes
+
+_importer._add_module(Module_six_moves_urllib_parse(__name__ + ".moves.urllib_parse"),
+                      "moves.urllib_parse", "moves.urllib.parse")
+
+
+class Module_six_moves_urllib_error(_LazyModule):
+
+    """Lazy loading of moved objects in six.moves.urllib_error"""
+
+
+_urllib_error_moved_attributes = [
+    MovedAttribute("URLError", "urllib2", "urllib.error"),
+    MovedAttribute("HTTPError", "urllib2", "urllib.error"),
+    MovedAttribute("ContentTooShortError", "urllib", "urllib.error"),
+]
+for attr in _urllib_error_moved_attributes:
+    setattr(Module_six_moves_urllib_error, attr.name, attr)
+del attr
+
+Module_six_moves_urllib_error._moved_attributes = _urllib_error_moved_attributes
+
+_importer._add_module(Module_six_moves_urllib_error(__name__ + ".moves.urllib.error"),
+                      "moves.urllib_error", "moves.urllib.error")
+
+
+class Module_six_moves_urllib_request(_LazyModule):
+
+    """Lazy loading of moved objects in six.moves.urllib_request"""
+
+
+_urllib_request_moved_attributes = [
+    MovedAttribute("urlopen", "urllib2", "urllib.request"),
+    MovedAttribute("install_opener", "urllib2", "urllib.request"),
+    MovedAttribute("build_opener", "urllib2", "urllib.request"),
+    MovedAttribute("pathname2url", "urllib", "urllib.request"),
+    MovedAttribute("url2pathname", "urllib", "urllib.request"),
+    MovedAttribute("getproxies", "urllib", "urllib.request"),
+    MovedAttribute("Request", "urllib2", "urllib.request"),
+    MovedAttribute("OpenerDirector", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPDefaultErrorHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPRedirectHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPCookieProcessor", "urllib2", "urllib.request"),
+    MovedAttribute("ProxyHandler", "urllib2", "urllib.request"),
+    MovedAttribute("BaseHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPPasswordMgr", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPPasswordMgrWithDefaultRealm", "urllib2", "urllib.request"),
+    MovedAttribute("AbstractBasicAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPBasicAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("ProxyBasicAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("AbstractDigestAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPDigestAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("ProxyDigestAuthHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPSHandler", "urllib2", "urllib.request"),
+    MovedAttribute("FileHandler", "urllib2", "urllib.request"),
+    MovedAttribute("FTPHandler", "urllib2", "urllib.request"),
+    MovedAttribute("CacheFTPHandler", "urllib2", "urllib.request"),
+    MovedAttribute("UnknownHandler", "urllib2", "urllib.request"),
+    MovedAttribute("HTTPErrorProcessor", "urllib2", "urllib.request"),
+    MovedAttribute("urlretrieve", "urllib", "urllib.request"),
+    MovedAttribute("urlcleanup", "urllib", "urllib.request"),
+    MovedAttribute("URLopener", "urllib", "urllib.request"),
+    MovedAttribute("FancyURLopener", "urllib", "urllib.request"),
+    MovedAttribute("proxy_bypass", "urllib", "urllib.request"),
+]
+for attr in _urllib_request_moved_attributes:
+    setattr(Module_six_moves_urllib_request, attr.name, attr)
+del attr
+
+Module_six_moves_urllib_request._moved_attributes = _urllib_request_moved_attributes
+
+_importer._add_module(Module_six_moves_urllib_request(__name__ + ".moves.urllib.request"),
+                      "moves.urllib_request", "moves.urllib.request")
+
+
+class Module_six_moves_urllib_response(_LazyModule):
+
+    """Lazy loading of moved objects in six.moves.urllib_response"""
+
+
+_urllib_response_moved_attributes = [
+    MovedAttribute("addbase", "urllib", "urllib.response"),
+    MovedAttribute("addclosehook", "urllib", "urllib.response"),
+    MovedAttribute("addinfo", "urllib", "urllib.response"),
+    MovedAttribute("addinfourl", "urllib", "urllib.response"),
+]
+for attr in _urllib_response_moved_attributes:
+    setattr(Module_six_moves_urllib_response, attr.name, attr)
+del attr
+
+Module_six_moves_urllib_response._moved_attributes = _urllib_response_moved_attributes
+
+_importer._add_module(Module_six_moves_urllib_response(__name__ + ".moves.urllib.response"),
+                      "moves.urllib_response", "moves.urllib.response")
+
+
+class Module_six_moves_urllib_robotparser(_LazyModule):
+
+    """Lazy loading of moved objects in six.moves.urllib_robotparser"""
+
+
+_urllib_robotparser_moved_attributes = [
+    MovedAttribute("RobotFileParser", "robotparser", "urllib.robotparser"),
+]
+for attr in _urllib_robotparser_moved_attributes:
+    setattr(Module_six_moves_urllib_robotparser, attr.name, attr)
+del attr
+
+Module_six_moves_urllib_robotparser._moved_attributes = _urllib_robotparser_moved_attributes
+
+_importer._add_module(Module_six_moves_urllib_robotparser(__name__ + ".moves.urllib.robotparser"),
+                      "moves.urllib_robotparser", "moves.urllib.robotparser")
+
+
+class Module_six_moves_urllib(types.ModuleType):
+
+    """Create a six.moves.urllib namespace that resembles the Python 3 namespace"""
+    __path__ = []  # mark as package
+    parse = _importer._get_module("moves.urllib_parse")
+    error = _importer._get_module("moves.urllib_error")
+    request = _importer._get_module("moves.urllib_request")
+    response = _importer._get_module("moves.urllib_response")
+    robotparser = _importer._get_module("moves.urllib_robotparser")
+
+    def __dir__(self):
+        return ['parse', 'error', 'request', 'response', 'robotparser']
+
+_importer._add_module(Module_six_moves_urllib(__name__ + ".moves.urllib"),
+                      "moves.urllib")
+
+
+def add_move(move):
+    """Add an item to six.moves."""
+    setattr(_MovedItems, move.name, move)
+
+
+def remove_move(name):
+    """Remove item from six.moves."""
+    try:
+        delattr(_MovedItems, name)
+    except AttributeError:
+        try:
+            del moves.__dict__[name]
+        except KeyError:
+            raise AttributeError("no such move, %r" % (name,))
+
+
+if PY3:
+    _meth_func = "__func__"
+    _meth_self = "__self__"
+
+    _func_closure = "__closure__"
+    _func_code = "__code__"
+    _func_defaults = "__defaults__"
+    _func_globals = "__globals__"
+else:
+    _meth_func = "im_func"
+    _meth_self = "im_self"
+
+    _func_closure = "func_closure"
+    _func_code = "func_code"
+    _func_defaults = "func_defaults"
+    _func_globals = "func_globals"
+
+
+try:
+    advance_iterator = next
+except NameError:
+    def advance_iterator(it):
+        return it.next()
+next = advance_iterator
+
+
+try:
+    callable = callable
+except NameError:
+    def callable(obj):
+        return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)
+
+
+if PY3:
+    def get_unbound_function(unbound):
+        return unbound
+
+    create_bound_method = types.MethodType
+
+    def create_unbound_method(func, cls):
+        return func
+
+    Iterator = object
+else:
+    def get_unbound_function(unbound):
+        return unbound.im_func
+
+    def create_bound_method(func, obj):
+        return types.MethodType(func, obj, obj.__class__)
+
+    def create_unbound_method(func, cls):
+        return types.MethodType(func, None, cls)
+
+    class Iterator(object):
+
+        def next(self):
+            return type(self).__next__(self)
+
+    callable = callable
+_add_doc(get_unbound_function,
+         """Get the function out of a possibly unbound function""")
+
+
+get_method_function = operator.attrgetter(_meth_func)
+get_method_self = operator.attrgetter(_meth_self)
+get_function_closure = operator.attrgetter(_func_closure)
+get_function_code = operator.attrgetter(_func_code)
+get_function_defaults = operator.attrgetter(_func_defaults)
+get_function_globals = operator.attrgetter(_func_globals)
+
+
+if PY3:
+    def iterkeys(d, **kw):
+        return iter(d.keys(**kw))
+
+    def itervalues(d, **kw):
+        return iter(d.values(**kw))
+
+    def iteritems(d, **kw):
+        return iter(d.items(**kw))
+
+    def iterlists(d, **kw):
+        return iter(d.lists(**kw))
+
+    viewkeys = operator.methodcaller("keys")
+
+    viewvalues = operator.methodcaller("values")
+
+    viewitems = operator.methodcaller("items")
+else:
+    def iterkeys(d, **kw):
+        return d.iterkeys(**kw)
+
+    def itervalues(d, **kw):
+        return d.itervalues(**kw)
+
+    def iteritems(d, **kw):
+        return d.iteritems(**kw)
+
+    def iterlists(d, **kw):
+        return d.iterlists(**kw)
+
+    viewkeys = operator.methodcaller("viewkeys")
+
+    viewvalues = operator.methodcaller("viewvalues")
+
+    viewitems = operator.methodcaller("viewitems")
+
+_add_doc(iterkeys, "Return an iterator over the keys of a dictionary.")
+_add_doc(itervalues, "Return an iterator over the values of a dictionary.")
+_add_doc(iteritems,
+         "Return an iterator over the (key, value) pairs of a dictionary.")
+_add_doc(iterlists,
+         "Return an iterator over the (key, [values]) pairs of a dictionary.")
+
+
+if PY3:
+    def b(s):
+        return s.encode("latin-1")
+
+    def u(s):
+        return s
+    unichr = chr
+    import struct
+    int2byte = struct.Struct(">B").pack
+    del struct
+    byte2int = operator.itemgetter(0)
+    indexbytes = operator.getitem
+    iterbytes = iter
+    import io
+    StringIO = io.StringIO
+    BytesIO = io.BytesIO
+    _assertCountEqual = "assertCountEqual"
+    if sys.version_info[1] <= 1:
+        _assertRaisesRegex = "assertRaisesRegexp"
+        _assertRegex = "assertRegexpMatches"
+    else:
+        _assertRaisesRegex = "assertRaisesRegex"
+        _assertRegex = "assertRegex"
+else:
+    def b(s):
+        return s
+    # Workaround for standalone backslash
+
+    def u(s):
+        return unicode(s.replace(r'\\', r'\\\\'), "unicode_escape")
+    unichr = unichr
+    int2byte = chr
+
+    def byte2int(bs):
+        return ord(bs[0])
+
+    def indexbytes(buf, i):
+        return ord(buf[i])
+    iterbytes = functools.partial(itertools.imap, ord)
+    import StringIO
+    StringIO = BytesIO = StringIO.StringIO
+    _assertCountEqual = "assertItemsEqual"
+    _assertRaisesRegex = "assertRaisesRegexp"
+    _assertRegex = "assertRegexpMatches"
+_add_doc(b, """Byte literal""")
+_add_doc(u, """Text literal""")
+
+
+def assertCountEqual(self, *args, **kwargs):
+    return getattr(self, _assertCountEqual)(*args, **kwargs)
+
+
+def assertRaisesRegex(self, *args, **kwargs):
+    return getattr(self, _assertRaisesRegex)(*args, **kwargs)
+
+
+def assertRegex(self, *args, **kwargs):
+    return getattr(self, _assertRegex)(*args, **kwargs)
+
+
+if PY3:
+    exec_ = getattr(moves.builtins, "exec")
+
+    def reraise(tp, value, tb=None):
+        if value is None:
+            value = tp()
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+else:
+    def exec_(_code_, _globs_=None, _locs_=None):
+        """Execute code in a namespace."""
+        if _globs_ is None:
+            frame = sys._getframe(1)
+            _globs_ = frame.f_globals
+            if _locs_ is None:
+                _locs_ = frame.f_locals
+            del frame
+        elif _locs_ is None:
+            _locs_ = _globs_
+        exec("""exec _code_ in _globs_, _locs_""")
+
+    exec_("""def reraise(tp, value, tb=None):
+    raise tp, value, tb
+""")
+
+
+if sys.version_info[:2] == (3, 2):
+    exec_("""def raise_from(value, from_value):
+    if from_value is None:
+        raise value
+    raise value from from_value
+""")
+elif sys.version_info[:2] > (3, 2):
+    exec_("""def raise_from(value, from_value):
+    raise value from from_value
+""")
+else:
+    def raise_from(value, from_value):
+        raise value
+
+
+print_ = getattr(moves.builtins, "print", None)
+if print_ is None:
+    def print_(*args, **kwargs):
+        """The new-style print function for Python 2.4 and 2.5."""
+        fp = kwargs.pop("file", sys.stdout)
+        if fp is None:
+            return
+
+        def write(data):
+            if not isinstance(data, basestring):
+                data = str(data)
+            # If the file has an encoding, encode unicode with it.
+            if (isinstance(fp, file) and
+                    isinstance(data, unicode) and
+                    fp.encoding is not None):
+                errors = getattr(fp, "errors", None)
+                if errors is None:
+                    errors = "strict"
+                data = data.encode(fp.encoding, errors)
+            fp.write(data)
+        want_unicode = False
+        sep = kwargs.pop("sep", None)
+        if sep is not None:
+            if isinstance(sep, unicode):
+                want_unicode = True
+            elif not isinstance(sep, str):
+                raise TypeError("sep must be None or a string")
+        end = kwargs.pop("end", None)
+        if end is not None:
+            if isinstance(end, unicode):
+                want_unicode = True
+            elif not isinstance(end, str):
+                raise TypeError("end must be None or a string")
+        if kwargs:
+            raise TypeError("invalid keyword arguments to print()")
+        if not want_unicode:
+            for arg in args:
+                if isinstance(arg, unicode):
+                    want_unicode = True
+                    break
+        if want_unicode:
+            newline = unicode("\n")
+            space = unicode(" ")
+        else:
+            newline = "\n"
+            space = " "
+        if sep is None:
+            sep = space
+        if end is None:
+            end = newline
+        for i, arg in enumerate(args):
+            if i:
+                write(sep)
+            write(arg)
+        write(end)
+if sys.version_info[:2] < (3, 3):
+    _print = print_
+
+    def print_(*args, **kwargs):
+        fp = kwargs.get("file", sys.stdout)
+        flush = kwargs.pop("flush", False)
+        _print(*args, **kwargs)
+        if flush and fp is not None:
+            fp.flush()
+
+_add_doc(reraise, """Reraise an exception.""")
+
+if sys.version_info[0:2] < (3, 4):
+    def wraps(wrapped, assigned=functools.WRAPPER_ASSIGNMENTS,
+              updated=functools.WRAPPER_UPDATES):
+        def wrapper(f):
+            f = functools.wraps(wrapped, assigned, updated)(f)
+            f.__wrapped__ = wrapped
+            return f
+        return wrapper
+else:
+    wraps = functools.wraps
+
+
+def with_metaclass(meta, *bases):
+    """Create a base class with a metaclass."""
+    # This requires a bit of explanation: the basic idea is to make a dummy
+    # metaclass for one level of class instantiation that replaces itself with
+    # the actual metaclass.
+    class metaclass(meta):
+
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+    return type.__new__(metaclass, 'temporary_class', (), {})
+
+
+def add_metaclass(metaclass):
+    """Class decorator for creating a class with a metaclass."""
+    def wrapper(cls):
+        orig_vars = cls.__dict__.copy()
+        slots = orig_vars.get('__slots__')
+        if slots is not None:
+            if isinstance(slots, str):
+                slots = [slots]
+            for slots_var in slots:
+                orig_vars.pop(slots_var)
+        orig_vars.pop('__dict__', None)
+        orig_vars.pop('__weakref__', None)
+        return metaclass(cls.__name__, cls.__bases__, orig_vars)
+    return wrapper
+
+
+def python_2_unicode_compatible(klass):
+    """
+    A decorator that defines __unicode__ and __str__ methods under Python 2.
+    Under Python 3 it does nothing.
+
+    To support Python 2 and 3 with a single code base, define a __str__ method
+    returning text and apply this decorator to the class.
+    """
+    if PY2:
+        if '__str__' not in klass.__dict__:
+            raise ValueError("@python_2_unicode_compatible cannot be applied "
+                             "to %s because it doesn't define __str__()." %
+                             klass.__name__)
+        klass.__unicode__ = klass.__str__
+        klass.__str__ = lambda self: self.__unicode__().encode('utf-8')
+    return klass
+
+
+# Complete the moves implementation.
+# This code is at the end of this module to speed up module loading.
+# Turn this module into a package.
+__path__ = []  # required for PEP 302 and PEP 451
+__package__ = __name__  # see PEP 366 @ReservedAssignment
+if globals().get("__spec__") is not None:
+    __spec__.submodule_search_locations = []  # PEP 451 @UndefinedVariable
+# Remove other six meta path importers, since they cause problems. This can
+# happen if six is removed from sys.modules and then reloaded. (Setuptools does
+# this for some reason.)
+if sys.meta_path:
+    for i, importer in enumerate(sys.meta_path):
+        # Here's some real nastiness: Another "instance" of the six module might
+        # be floating around. Therefore, we can't use isinstance() to check for
+        # the six meta path importer, since the other six instance will have
+        # inserted an importer with different class.
+        if (type(importer).__name__ == "_SixMetaPathImporter" and
+                importer.name == __name__):
+            del sys.meta_path[i]
+            break
+    del i, importer
+# Finally, add the importer to the meta path import hook.
+sys.meta_path.append(_importer)
diff --git a/setuptools/_vendor/vendored.txt b/setuptools/_vendor/vendored.txt
new file mode 100644
index 00000000..b6e34eb2
--- /dev/null
+++ b/setuptools/_vendor/vendored.txt
@@ -0,0 +1 @@
+six==1.10.0
diff --git a/setuptools/bootstrap.py b/setuptools/bootstrap.py
deleted file mode 100644
index 0cd95778..00000000
--- a/setuptools/bootstrap.py
+++ /dev/null
@@ -1,27 +0,0 @@
-"""
-When setuptools is installed in a clean environment, it doesn't have its
-dependencies, so it can't run to install its dependencies. This module
-checks those dependencies and if one or more are missing, it uses vendored
-versions.
-"""
-
-import os
-import sys
-import glob
-
-def ensure_deps():
-	"""
-	Detect if dependencies are installed and if not, use vendored versions.
-	"""
-	try:
-		__import__('six')
-	except ImportError:
-		use_vendor_deps()
-
-def use_vendor_deps():
-	"""
-	Use vendored versions
-	"""
-	here = os.path.dirname(__file__)
-	eggs = glob.glob(here + '/_vendor/*.egg')
-	sys.path.extend(eggs)
diff --git a/setuptools/command/bdist_egg.py b/setuptools/command/bdist_egg.py
index 73f8e3f1..78164819 100644
--- a/setuptools/command/bdist_egg.py
+++ b/setuptools/command/bdist_egg.py
@@ -11,7 +11,12 @@ import os
 import marshal
 import textwrap
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from pkg_resources import get_build_platform, Distribution, ensure_directory
 from pkg_resources import EntryPoint
diff --git a/setuptools/command/develop.py b/setuptools/command/develop.py
index ef9ac22d..c401c8d4 100755
--- a/setuptools/command/develop.py
+++ b/setuptools/command/develop.py
@@ -5,7 +5,12 @@ import os
 import glob
 import io
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from pkg_resources import Distribution, PathMetadata, normalize_path
 from setuptools.command.easy_install import easy_install
diff --git a/setuptools/command/easy_install.py b/setuptools/command/easy_install.py
index 6aab38c8..51c38ddf 100755
--- a/setuptools/command/easy_install.py
+++ b/setuptools/command/easy_install.py
@@ -40,8 +40,14 @@ import subprocess
 import shlex
 import io
 
-import six
-from six.moves import configparser
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import configparser
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import configparser
 
 from setuptools import Command
 from setuptools.sandbox import run_setup
diff --git a/setuptools/command/egg_info.py b/setuptools/command/egg_info.py
index 19849e66..5b996a11 100755
--- a/setuptools/command/egg_info.py
+++ b/setuptools/command/egg_info.py
@@ -14,7 +14,12 @@ import io
 import warnings
 import time
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from setuptools import Command
 from setuptools.command.sdist import sdist
diff --git a/setuptools/command/rotate.py b/setuptools/command/rotate.py
index 09eac496..1ee1c538 100755
--- a/setuptools/command/rotate.py
+++ b/setuptools/command/rotate.py
@@ -3,7 +3,12 @@ from distutils import log
 from distutils.errors import DistutilsOptionError
 import os
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from setuptools import Command
 
diff --git a/setuptools/command/sdist.py b/setuptools/command/sdist.py
index 3b9f7dd5..59990cd6 100755
--- a/setuptools/command/sdist.py
+++ b/setuptools/command/sdist.py
@@ -5,7 +5,12 @@ import os
 import sys
 import io
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from setuptools.utils import cs_path_exists
 
diff --git a/setuptools/command/setopt.py b/setuptools/command/setopt.py
index f78e0cd5..1441e512 100755
--- a/setuptools/command/setopt.py
+++ b/setuptools/command/setopt.py
@@ -4,7 +4,12 @@ from distutils.errors import DistutilsOptionError
 import distutils
 import os
 
-from six.moves import configparser
+try:
+    from setuptools._vendor.six.moves import configparser
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    from six.moves import configparser
 
 from setuptools import Command
 
diff --git a/setuptools/command/test.py b/setuptools/command/test.py
index 5f2e2299..32ff7f15 100644
--- a/setuptools/command/test.py
+++ b/setuptools/command/test.py
@@ -2,7 +2,12 @@ from distutils.errors import DistutilsOptionError
 from unittest import TestLoader
 import sys
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from pkg_resources import (resource_listdir, resource_exists, normalize_path,
                            working_set, _namespace_packages,
diff --git a/setuptools/command/upload_docs.py b/setuptools/command/upload_docs.py
index 43b5d76a..60e9fb7e 100644
--- a/setuptools/command/upload_docs.py
+++ b/setuptools/command/upload_docs.py
@@ -16,8 +16,14 @@ import tempfile
 import sys
 import shutil
 
-from six.moves import http_client, urllib
-import six
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import http_client, urllib
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import http_client, urllib
 
 from pkg_resources import iter_entry_points
 
diff --git a/setuptools/depends.py b/setuptools/depends.py
index 43617e6d..e633c05b 100644
--- a/setuptools/depends.py
+++ b/setuptools/depends.py
@@ -4,7 +4,12 @@ import marshal
 from imp import PKG_DIRECTORY, PY_COMPILED, PY_SOURCE, PY_FROZEN
 from distutils.version import StrictVersion
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 __all__ = [
     'Require', 'find_module', 'get_module_constant', 'extract_constant'
diff --git a/setuptools/dist.py b/setuptools/dist.py
index 7335c967..11b42d19 100644
--- a/setuptools/dist.py
+++ b/setuptools/dist.py
@@ -13,7 +13,12 @@ from distutils.core import Distribution as _Distribution
 from distutils.errors import (DistutilsOptionError, DistutilsPlatformError,
     DistutilsSetupError)
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 from setuptools.depends import Require
 from setuptools import windows_support
diff --git a/setuptools/package_index.py b/setuptools/package_index.py
index 657b467f..08c36890 100755
--- a/setuptools/package_index.py
+++ b/setuptools/package_index.py
@@ -14,8 +14,14 @@ try:
 except ImportError:
     from urllib2 import splituser
 
-import six
-from six.moves import urllib, http_client, configparser
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import urllib, http_client, configparser
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import urllib, http_client, configparser
 
 from pkg_resources import (
     CHECKOUT_DIST, Distribution, BINARY_DIST, normalize_path, SOURCE_DIST,
diff --git a/setuptools/sandbox.py b/setuptools/sandbox.py
index 43b84791..47d7f40c 100755
--- a/setuptools/sandbox.py
+++ b/setuptools/sandbox.py
@@ -8,8 +8,14 @@ import re
 import contextlib
 import pickle
 
-import six
-from six.moves import builtins
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import builtins
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import builtins
 
 import pkg_resources
 
diff --git a/setuptools/ssl_support.py b/setuptools/ssl_support.py
index 8fd7836b..327c2fcb 100644
--- a/setuptools/ssl_support.py
+++ b/setuptools/ssl_support.py
@@ -3,7 +3,12 @@ import socket
 import atexit
 import re
 
-from six.moves import urllib, http_client
+try:
+    from setuptools._vendor.six.moves import urllib, http_client
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    from six.moves import urllib, http_client
 
 import pkg_resources
 from pkg_resources import ResolutionError, ExtractionError
diff --git a/setuptools/tests/__init__.py b/setuptools/tests/__init__.py
index b2c6894f..0a625993 100644
--- a/setuptools/tests/__init__.py
+++ b/setuptools/tests/__init__.py
@@ -8,7 +8,12 @@ from distutils.errors import DistutilsSetupError
 from distutils.core import Extension
 from distutils.version import LooseVersion
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 import pytest
 
 import setuptools.dist
diff --git a/setuptools/tests/contexts.py b/setuptools/tests/contexts.py
index d9dcad84..3a0ce6b5 100644
--- a/setuptools/tests/contexts.py
+++ b/setuptools/tests/contexts.py
@@ -5,7 +5,12 @@ import sys
 import contextlib
 import site
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 
 @contextlib.contextmanager
diff --git a/setuptools/tests/server.py b/setuptools/tests/server.py
index 1fee0563..ef5c8f62 100644
--- a/setuptools/tests/server.py
+++ b/setuptools/tests/server.py
@@ -4,7 +4,13 @@
 import time
 import threading
 
-from six.moves import BaseHTTPServer, SimpleHTTPServer
+try:
+    from setuptools._vendor.six.moves import BaseHTTPServer, SimpleHTTPServer
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    from six.moves import BaseHTTPServer, SimpleHTTPServer
+
 
 class IndexServer(BaseHTTPServer.HTTPServer):
     """Basic single-threaded http server simulating a package index
diff --git a/setuptools/tests/test_bdist_egg.py b/setuptools/tests/test_bdist_egg.py
index f8a68378..ccfb2ea7 100644
--- a/setuptools/tests/test_bdist_egg.py
+++ b/setuptools/tests/test_bdist_egg.py
@@ -3,7 +3,6 @@
 import os
 import re
 
-import six
 import pytest
 
 from setuptools.dist import Distribution
diff --git a/setuptools/tests/test_develop.py b/setuptools/tests/test_develop.py
index 236b3aa6..71aaed6a 100644
--- a/setuptools/tests/test_develop.py
+++ b/setuptools/tests/test_develop.py
@@ -5,7 +5,12 @@ import site
 import sys
 import io
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 import pytest
 
diff --git a/setuptools/tests/test_easy_install.py b/setuptools/tests/test_easy_install.py
index 30220b7f..de34ca27 100644
--- a/setuptools/tests/test_easy_install.py
+++ b/setuptools/tests/test_easy_install.py
@@ -16,8 +16,15 @@ import itertools
 import distutils.errors
 import io
 
-import six
-from six.moves import urllib
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import urllib
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import urllib
+
 import pytest
 try:
     from unittest import mock
diff --git a/setuptools/tests/test_integration.py b/setuptools/tests/test_integration.py
index 11a6ff5a..1c574020 100644
--- a/setuptools/tests/test_integration.py
+++ b/setuptools/tests/test_integration.py
@@ -7,7 +7,13 @@ import glob
 import os
 import sys
 
-from six.moves import urllib
+try:
+    from setuptools._vendor.six.moves import urllib
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    from six.moves import urllib
+
 
 import pytest
 
diff --git a/setuptools/tests/test_packageindex.py b/setuptools/tests/test_packageindex.py
index dca4c2aa..649e8a4e 100644
--- a/setuptools/tests/test_packageindex.py
+++ b/setuptools/tests/test_packageindex.py
@@ -4,8 +4,14 @@ import sys
 import os
 import distutils.errors
 
-import six
-from six.moves import urllib, http_client
+try:
+    from setuptools._vendor import six
+    from setuptools._vendor.six.moves import urllib, http_client
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+    from six.moves import urllib, http_client
 
 from .textwrap import DALS
 import pkg_resources
diff --git a/setuptools/tests/test_sdist.py b/setuptools/tests/test_sdist.py
index c173d713..ea176733 100644
--- a/setuptools/tests/test_sdist.py
+++ b/setuptools/tests/test_sdist.py
@@ -9,7 +9,13 @@ import unicodedata
 import contextlib
 import io
 
-import six
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
+
 import pytest
 
 import pkg_resources
diff --git a/setuptools/tests/test_test.py b/setuptools/tests/test_test.py
index 6587dc40..4155a5b1 100644
--- a/setuptools/tests/test_test.py
+++ b/setuptools/tests/test_test.py
@@ -6,7 +6,6 @@ import os
 import site
 from distutils.errors import DistutilsError
 
-import six
 import pytest
 
 from setuptools.command.test import test
diff --git a/setuptools/unicode_utils.py b/setuptools/unicode_utils.py
index f028589e..1fdb0a91 100644
--- a/setuptools/unicode_utils.py
+++ b/setuptools/unicode_utils.py
@@ -1,7 +1,13 @@
 import unicodedata
 import sys
 
-import six
+
+try:
+    from setuptools._vendor import six
+except ImportError:
+    # fallback to naturally-installed version; allows system packagers to
+    #  omit vendored packages.
+    import six
 
 # HFS Plus uses decomposed UTF-8
 def decompose(path):