Distutils apparently requires an absolute path so provide one.

neil.schemenauer · neil.schemenauer · commit 88e058929aaf · 2009-02-06T00:21:55.000Z
git-svn-id: http://svn.python.org/projects/python/trunk@69322 6015fed2-1504-0410-9fe1-9d1591cc4771
diff --git a/setup.py b/setup.py
@@ -118,7 +118,7 @@ def build_extensions(self):
         if not srcdir:
             # Maybe running on Windows but not using CYGWIN?
             raise ValueError("No source directory; cannot proceed.")
-        srcdir = os.path.normpath(srcdir)
+        srcdir = os.path.abspath(srcdir)
         moddirlist = [os.path.join(srcdir, 'Modules')]
 
         # Platform-dependent module source and include directories
