While getting wxPython 3 working with GTK3, I observed that when inserting pages into a wxNotebook, GTK warnings are issued. The wxPython demo application uses wxNotebook extensively so there are many warnings. The warnings can also be observed by running the notebook sample from wxWidgets. Upstream has a fix for this. It would be very helpful if this patch could be cherry-picked into the Fedora build. https://github.com/wxWidgets/wxWidgets/commit/6be8cbcc43f83953f3e869b341ea92aa0cb2abe4 Thanks.
Ok I'll include this commit as a patch
Sorry this was fixed a while ago in fedora (3.0.1-3or4 ish?), and upstream in 3.0.2. 3.0.2 should be in testing now and in rawhide, sorry for the delay.