TypeError when trying to get detailed info about command

[renskiy]

fab -d test
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/fabric/main.py", line 694, in main
    display_command(options.display)
  File "/Library/Python/2.7/site-packages/fabric/main.py", line 479, in display_command
    task_details = command.__details__()
  File "/Library/Python/2.7/site-packages/fabric/tasks.py", line 183, in __details__
    return get_task_details(orig)
  File "/Library/Python/2.7/site-packages/fabric/tasks.py", line 42, in get_task_details
    argspec = inspect.getargspec(task)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 816, in getargspec
    raise TypeError('{!r} is not a Python function'.format(func))
TypeError: <functools.partial object at 0x10c9a2260> is not a Python function