This a problem I have not encountered before. I'm trying to compile a copy of garglk, just downloaded the code. This is for a Fedora 21, 64-bit system.
The jam manager is complaining:
No package 'gtk+-x11-2.0' found
No package 'gtk+-x11-2.0' found
and I have no idea where to find these. The devel packages for both gtk+ and gtk+2 are installed.