In changeset 88c3a1a3c2ff you'll find in test_api.py where I threw together a __path__ to compare against the one I was getting (which had 2 identical entries) on my Ubuntu 12.04 workstation. The XP buildbot (http://buildbot.python.org/all/builders/x86%20XP-4%203.x) took issue with that (but non-windows was fine). I was able to work around the difference (78d36d54391c), but I find the extra namespace portions surprising. I'd like to get to the bottom of it. I expect it has to do with how path entries are done on Windows, or perhaps with the way support.temp_cwd() iteracts with sys.path during testing.
FWIW, this bug has bitten Django; see https://code.djangoproject.com/ticket/25246 We can easily work around it for future versions, but we have code in released versions that assumed that `__path__` wouldn't contain dupes; it causes us to raise an error in a situation that shouldn't be an error (because we need a Django "app" module to have exactly one filesystem location).
I can't reproduce under Python 3.4.3, the 3.4 branch, 3.5 branch, or default with a plain namespace package. Can anyone come up with a test case that can reproduce this problem? Otherwise I'll assume it was a bug that got fixed in 3.4.2.
