Do not patch Makefile.in, patch Makefile.am and rebuild autotools, please.
This package has its Makefile.ams and Makefile.ins out of sync. Apparently upstream decided that modifying Makefile.in (instead of Makefile.am) to add gtk (and other) stuff was a nice idea. So regenerating autotools on this package results in inability to compile it :-/
Since the patch applied to this package does not trigger a dual ./configure run, I'm unwilling to fix this.
Feel free to reopen if you think it necessary...