Funny, I didn't look where these substitutions were occurring... I only saw that they existed. src/bitmessagemain.py is already pointing to /usr/bin/env python2.7, so that's fine. The other instances of "/usr/bin/env python" should be deleted anyway, since they are never to be executed. /usr/bin/pybitmessage indeed needs to be fixed to be python2. Otherwise the package looks like it should do.