I am using argparse-1.4.0.

For this code exception is thrown when the script is started with the -h option:
http://pastebin.com/dFF1paFA

This exception is thrown:
Traceback (most recent call last):
  File "C:\Users\ebak\Picea\tools\buildsystem\python\kw_set_checkers.py", line 129, in <module>
    args = parser.parse_args()
  File "C:\Python27\lib\argparse.py", line 1688, in parse_args
    args, argv = self.parse_known_args(args, namespace)
  File "C:\Python27\lib\argparse.py", line 1720, in parse_known_args
    namespace, args = self._parse_known_args(args, namespace)
  File "C:\Python27\lib\argparse.py", line 1926, in _parse_known_args
    start_index = consume_optional(start_index)
  File "C:\Python27\lib\argparse.py", line 1866, in consume_optional
    take_action(action, args, option_string)
  File "C:\Python27\lib\argparse.py", line 1794, in take_action
    action(self, namespace, argument_values, option_string)
  File "C:\Python27\lib\argparse.py", line 994, in __call__
    parser.print_help()
  File "C:\Python27\lib\argparse.py", line 2327, in print_help
    self._print_message(self.format_help(), file)
  File "C:\Python27\lib\argparse.py", line 2301, in format_help
    return formatter.format_help()
  File "C:\Python27\lib\argparse.py", line 279, in format_help
    help = self._root_section.format_help()
  File "C:\Python27\lib\argparse.py", line 209, in format_help
    func(*args)
  File "C:\Python27\lib\argparse.py", line 317, in _format_usage
    action_usage = format(optionals + positionals, groups)
  File "C:\Python27\lib\argparse.py", line 388, in _format_actions_usage
    start = actions.index(group._group_actions[0])
IndexError: list index out of range