>>> repo.remotes.origin.fetch()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/site-packages/git/remote.py", line 550, in fetch
return self._get_fetch_info_from_stderr(proc, progress or RemoteProgress())
File "/usr/local/lib/python2.7/site-packages/git/remote.py", line 497, in _get_fetch_info_from_stderr
assert len(fetch_info_lines) == len(fetch_head_info)
AssertionError