10 files changed, 56 insertions, 12 deletions
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