Comment # 28 on bug 56405 from Michael Dressel

(In reply to comment #27)
> (In reply to comment #26)
> > (In reply to comment #25)
> >  LIBGL_DEBUG=verbose glxinfo | grep render
> I don't have glxinfo

Ah I found it on archlinux AUR in the
package mesa-demo-git. I'm just
building it.