I created a basic gtk3 package in AUR, though later I noticed that there is a gnome-unstable repository, with gtk3 in it. Please delete my gtk3 package in AUR, I don't want it to start conflicting with gnome-unstable things and it is also redundant as it turns out. So I guess it is probably unwanted, or else let me know and I'll keep maintaining it until it gets stable. Thank you and sorry for the trouble.