ModuleFinder.load_module currently only skips 8 bytes before trying to marshal.load the rest of the file, but it should skip 12 since 3.3 (magic, date, file size). I'm attaching a patch with test case.

BTW this was very painful to find out, since I couldn't find any reference to written pyc files - am I searching wrong or is this really not documented anywhere?

(Note, that this was originally reported at https://bugzilla.redhat.com/show_bug.cgi?id=1060338).