mingw-gtk3 got retired in the recent FTBFS cleanup. Please unretire it and unblock in f31. I'll take care of fixing the FTBFS.
Metadata Update from @ignatenkobrain: - Issue assigned to ignatenkobrain
Now you own it. Please fix FTBFS and make a build. Better before branching :)
Metadata Update from @ignatenkobrain: - Issue close_status updated to: Fixed - Issue status updated to: Closed (was: Open)