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

--HG--
branch : feature/issue-229

1 files changed, 8 insertions, 2 deletions

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