uu module on line 53 erroneously tries to catch an AttributeError
exception type.

            try:
                mode = os.stat(in_file).st_mode
            except AttributeError:
                pass

This is not correct since os.stat(), as far as I know, should raise
OSError exceptions only.
This would turn in an error in case we pass a "broken" symlink as
in_file argument.