it seams that for 0.7.0d-r1 version ebuild of net-p2p/gnunet (and probably for 0.6.2b too) that "gtk" flag has no effect: gnunet-gtk is not compiled (which is correct behaviour I guess because separate ebuild gnunet-gtk...) So "gtk" should be removed from IUSE?
Sorry, I was wrong, it seems that several other tools use gtk such as gnunet-setup - I see on gnunet.org page. Please close this bug as INAVLID
Closing. ;)