rust: Exclude empty node prefixes
We presumably don’t want `--rev ""` to select every single revision,
even though the empty string is a prefix of all strings.
Differential Revision: https://phab.mercurial-scm.org/D9862
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)