current ebuild requires to set either gtk2 or gtk3 if X use flag is enabled. according metadata.xml and ebuild X determines wheather to install nvidia-driver libraries required to use the nvidia drivers and tools use flag selects to install nvidia related tools as nvidia-settings. later in src_install the ebuild queries for tools and dependent on that installs libnvidia-gtk{2,3}.so according to use flags. in my opinion the REQUIRED_USE should be changed to reflect this behaviour and furthermore the gtk2 use flag should be changed to the global gtk one. Reproducible: Always
USE=gtk is supposed to be used to get the best available version, so that's not going to work here. 15 Nov 2014; Jeroen Roovers <jer@gentoo.org> nvidia-drivers-346.16.ebuild: Change REQUIRED_USE X? ( || ( gtk2 gtk3 ) ) to tools? ( || ( gtk gtk3 ) ) (bug #529362 by bwcknr).