packaging: require mercurial >= 4.5 Otherwise building the doc package fails with: (third party extension evolve requires version 4.5 or newer of Mercurial; disabling) Exception occurred: File "/usr/lib/python2.7/dist-packages/mercurial/help.py", line 624, in help_ raise error.Abort(msg, hint=hint) Abort: no such help topic: evolve

# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)