Glade doesn't support editing templates that derive from abstract classes
Submitted by Kalev Lember
In gnome-software we've got a number of widgets that derive from the abstract GtkBin class. Those are all uneditable in Glade.
Trying to load https://git.gnome.org/browse/gnome-software/tree/src/gs-star-widget.ui ends with Glade saying: "FIXME: Unable to create object with type GsStarWidget"