As noted in #15314, one of the pkgutil tests was failing on Windows because pkgutil.get_importer("") was returning None. On my Fedora system it returns FileFinder(".").

I've now tweaked that particular test to use a bogus path string so that None is the expected result on all platforms.

However, the cross-platform discrepancy is a little disturbing - I would have expected the operation to either fail or succeed regardless of platform.

Since pkgutil.get_importer is now just a wrapper that takes care of checking path_importer_cache and then walking sys.path_hooks, I believe the actual culprit is FileFinder.path_hook()("") returning None (I'm currently downloading and installing 3.3b1 on my gaming machine to confirm that)

Well, that's weird. A manual test on my Windows 7 gaming rig indicates that the old test *should* have worked on Windows as well.

I have no idea how to investigate this further. David, are you able to check what pkgutil.get_importer("") returns when running locally on your Windows buildbots?


An example of the error the buildbots were getting: http://buildbot.python.org/all/builders/x86%20Windows7%203.x/builds/5450/steps/test/logs/stdio

With a local build on my buildbot of the tip of the default branch, pkgutil.get_importer('') returns FileFilter('.').  The tests also passed.

However, after checking here and realizing the offending code had been removed from the test, I put it back in and it still fails.

I think the problem is that sys.path[0] is not '' when testing in the buildbot environment (though it is when I run the debug interpreter interactively).  Within the buildbot scripts it's a path to the stdlib test zip, so for example in my test tree it's "D:\cygwin\home\db3l\test\build\PCbuild\python33_d.zip".

And if I hand that string to pkgutil.get_importer() I do seem to get None back.

Ah, that makes sense - since the zip file doesn't exist on buildbots, returning None is the correct result.

Mystery explained, thanks :)