ERROR: 'module' object has no attribute 'add_arg'

gistfile1.txt

swilson@racker:~$ pip show os-diskconfig-python-novaclient-ext
---
Name: os-diskconfig-python-novaclient-ext
Version: 0.1.2
Location: /usr/local/lib/python2.7/dist-packages
Requires: python-novaclient
swilson@racker:~$ python
Python 2.7.3 (default, Sep 26 2013, 20:03:06) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os_diskconfig_python_novaclient_ext
>>> dir(os_diskconfig_python_novaclient_ext)
['API_DISK_CONFIG', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '__path__', '__post_parse_args__', '__pre_parse_args__', 'add_arg', 'add_args', 'add_modify_body_hook', 'bind_args_to_resource_manager', 'servers', 'shell', 'utils']
>>> 
ERROR: 'module' object has no attribute 'add_arg'
swilson@racker:~$ supernova -d inova-ord list
DEBUG (shell:777) 'module' object has no attribute 'add_arg'
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/novaclient/shell.py", line 774, in main
    OpenStackComputeShell().main(map(strutils.safe_decode, sys.argv[1:]))
  File "/usr/local/lib/python2.7/dist-packages/novaclient/shell.py", line 523, in main
    self._run_extension_hooks('__pre_parse_args__')
  File "/usr/local/lib/python2.7/dist-packages/novaclient/shell.py", line 730, in _run_extension_hooks
    extension.run_hooks(hook_type, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/novaclient/utils.py", line 320, in run_hooks
    hook_func(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/rax_default_network_flags_python_novaclient_ext/__init__.py", line 70, in __pre_parse_args__
    add_args()
  File "/usr/local/lib/python2.7/dist-packages/rax_default_network_flags_python_novaclient_ext/__init__.py", line 25, in add_args
    utils.add_arg(shell.do_boot,
AttributeError: 'module' object has no attribute 'add_arg'
ERROR: 'module' object has no attribute 'add_arg'