Nick Coghlan added the comment: Issue filed with six about this: https://github.com/benjaminp/six/issues/207 It turns out to be somewhat timely on that side as well, as it turns out that six has a not-yet-released change adding "six.moves.commands", which doesn't currently account for this inadvertent incompatibility in the way exit codes are reported. ---------- nosy: +benjamin.peterson _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue22635> _______________________________________