Merge branch 'master' into 225-dont_prefix_special_rpath_vars

dev.py

@@ -50,14 +50,15 @@ except ImportError:
 exec(urlopen('https://bootstrap.pypa.io/ez_setup.py').read(), ez)
 ez['use_setuptools'](to_dir='eggs', download_delay=0)
 
-import pkg_resources
+import pkg_resources, setuptools
+setuptools_path = os.path.dirname(os.path.dirname(setuptools.__file__))
 
 ######################################################################
 # Install buildout
 if subprocess.call(
     [sys.executable] +
     ['setup.py', '-q', 'develop', '-m', '-x', '-d', 'develop-eggs'],
-    env=dict(os.environ, PYTHONPATH=os.path.dirname(pkg_resources.__file__))):
+    env=dict(os.environ, PYTHONPATH=setuptools_path)):
     raise RuntimeError("buildout build failed.")
 
 pkg_resources.working_set.add_entry('src')