Control: severity -1 +important pygtk is unmaintained upstream. It has not had a release since GNOME 3 was released in 2011.
The way forward is to port your app to use GObject Introspection bindings (and gtk3) (as done in the patch previously provided here). For more information on GObject Introspection see [1] and [2]. Please try to do this before the Buster release as we're going to try to remove pygtk this cycle. If you have any question don't hesitate to ask. [1] https://wiki.gnome.org/Projects/GObjectIntrospection [2] https://wiki.gnome.org/Projects/PyGObject On behalf of the Debian GNOME team, Jeremy Bicha