If resourcepackage is used for an application and then
the application is bundled up into a zip (as the latest
py2exe does) for use with the new zipimport,
resourcepackage dies because it tries to list a directory
when the directory is actually a zip.
resourcepackage could perhaps be updated to rebuild
from a zip (it's possible, although unlikely, that the zip
would change), but that probably isn't necessary.
This can also be avoided by replacing the __init__.py in
the zip, so that resource package isn't used. Swapping
them in and out is a pain, though <wink>.
This very small patch avoids the problem by simply not
scanning anything that isn't a directory, which is
probably the intent, anyway.
(SpamBayes is the particular use case where this has
come up, but it seems fairly generic, especially once
using zipimport becomes more common).