I use dh_virtualenv OR `pip install --download-cache=vendor dist/package.tgz` in rpmbuild & `pip install --download vendor pckage.tgz` (+ virtualenv fiddling) i

I use dh_virtualenv OR `pip install --download-cache=vendor dist/package.tgz` in rpmbuild & `pip install --download vendor pckage.tgz` (+ virtualenv fiddling) in postinst