There's special syntax to handle aliases.  From comments in clinic.py:

        # alternatively:
        #     modulename.fnname [as c_basename] = modulename.existing_fn_name
        # clones the parameters and return converter from that
        # function.  you can't modify them.  you must enter a
        # new docstring.

Sorry the docs are out of date--patches welcome.  And speaking of patches, thanks for the patch!  I'll review it when you say it's ready.