@KevinH:
Yeah, it's not copying any files on Windows either.
It's only succeeding because technically ... nothing went wrong.
I've got it narrowed down to the call to unipath.walk("./payload") in __main__.py. It's returning an empty list instead of the files in the payload folder. Is it possible that something's different with accessing a folder "relatively" (./payload) inside a zipfile on Windows/Linux?