* Error: circular dependencies:
(x11-libs/libva-1.6.2:0/0::gentoo, ebuild scheduled for merge) depends on
(media-libs/mesa-12.0.1:0/0::gentoo, ebuild scheduled for merge) (buildtime)
(x11-libs/libva-1.6.2:0/0::gentoo, ebuild scheduled for merge) (buildtime_slot_op)

It might be possible to break this cycle
by applying any of the following changes:
-media-libs/mesa-12.0.1 (Change USE: -vaapi)
-x11-libs/libva-1.6.2 (Change USE: -egl)