On Tue, 13 Dec 2011 10:38:46 +0000, Patrick Totzke <patricktotzke@googlemail.com> wrote: > I have seen this before yes. It seems to be a problem with the python distribution on > debian. Apparently, you have two different versions of the argparse module installed: As > of 2.7, argparse is part of the standard lib, but debian ships a separate package > python-argparse. I just filed a Debian bug against python-argparse: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=651962 jamie.