Created attachment 2892 [details] Make gnome-ssh-askpass2 buildable with GTK+ 3 GTK+ 2 has not been the current version for a while (although some people still prefer it for one reason or another; I don't propose to get into that here). It's fairly easy to make gnome-ssh-askpass2 buildable using GTK+ 3 instead, and the attached patch does this.
Code changes applied. For the Makefile, I did it slightly differently - adding an explicit gnome-ssh-askpass3 target.
closing resolved bugs as of 8.6p1 release