$ python update.py ../gerritbot
usage: Usage: update.py [config-file|dest-dir]
update.py: error: unrecognized arguments: ../gerritbot

$ python update.py
Traceback (most recent call last):
  File "update.py", line 221, in <module>
    main(sys.argv[1:])
  File "update.py", line 195, in main
    conf = _parse_args(argv)
  File "update.py", line 89, in _parse_args
    if len(args) == 1:
TypeError: object of type 'NoneType' has no len()