https://bugs.freedesktop.org/show_bug.cgi?id=91993
--- Comment #15 from Nicolai Hähnle nhaehnle@gmail.com --- With the apitrace, I do see an obvious graphical glitch (looking slightly different than the attachment).
apitrace reports an error: api issue 1: FBO incomplete: no attachments [-1] in frame 0. I do not know whether this is related to the graphical glitch, but you should probably report it to AstroMenace in any case.