This has been discussed on desktop-devel-list@ in the past days, and the foundations for this are now ready:
- pygobject now has a –with-python option. (commit)
- JHBuild now defaults to building pygobject for Python 3, but introduces a “pygobject-python2” project for the transition phase which provides pygobject built for Python 2. (commit)
- All dependencies to “pygobject” were changed to “pygobject-python2” to avoid breaking modules. (commit).
So in theory your modules should continue to build and work in jhbuild just fine. Once you ported a module to Python 3, please switch the dependency back to “pygobject” in jhbuild. (This is now also mentioned on https://live.gnome.org/GnomeGoals/Python3Porting)
Please don’t hesitate to ask me or any fellow PyGObject maintainer in cases of trouble; I’m “pitti” in #python on irc.gnome.org.