Traceback (most recent call last):
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/commands.py", line 835, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/commands.py", line 1039, in run_bzr
    ret = run(*run_argv)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/commands.py", line 643, in run_argv_aliases
    return self.run_direct(**all_cmd_args)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/commands.py", line 647, in run_direct
    return self._operation.run_simple(*args, **kwargs)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/cleanup.py", line 122, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/cleanup.py", line 156, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/builtins.py", line 1020, in run
    possible_transports=possible_transports)
  File "/home/Checkouts/Bazaar/Bazaar/Mainline_Working/bzrlib/branch.py", line 170, in open
    return control.open_branch(unsupported=_unsupported)
TypeError: open_branch() got an unexpected keyword argument 'unsupported'