https://bugs.freedesktop.org/show_bug.cgi?id=87625
--- Comment #7 from Michel Dänzer michel@daenzer.net --- (In reply to Luke-Jr from comment #6)
I have glamor 0.6.0 - is that current? (Gentoo doesn't have anything newer, it seems)
That's the old standalone glamor tree. Please try glamor from xserver 1.16 or newer.