@gcbirzan: Could you please open up a new issue? The current issue is fixed - it's just that the fix caused a new issue.
I would say that the `args` parameter was never intended to be anything but a list, so currently there's a documentation bug since that isn't stated explicitly anywhere. (But certainly the tests only test for lists, not any other sequences.)
Adding support for stuff other than lists feels more like a feature request, but given that it apparently worked by accident before, I guess we need to treat it as a bug. Probably the fix for that bug needs to have a ton of tests that check whether tuples work in all the various ways that parse_args is used.