File "/home/username/pywikipedia/compat/config.py", line 578, in <module>

    for _filename in os.listdir(os.path.join(_base_dir, 'families')):
OSError: [Errno 2] No such file or directory: '/home/username/.pywikibot/families'

It's a bug and needs to be fixed but for a fast solution, copy your user-fixes.py and user-config.py to the compat folder I think It will erase the error but I need to fix it in long-term