When moving from the threading module to multiprocessing, I noticed my project's clean_sandbox.py script wouldn't finish executing because of line 104 which is self.site.login(). I'm not sure what's different between the multiprocessing module and threading that would make the Pywikibot login script break.
Commit: https://github.com/jdloft/bot24/commit/bbc4fffb47543805296d03d9efe3e4a4f426ce5b (multiprocessing branch)
Main script: https://github.com/jdloft/bot24/blob/multiprocessing/main.py
Clean_sandbox: https://github.com/jdloft/bot24/blob/multiprocessing/scripts/clean_sandbox.py#L104