nvidia driver, maxwell card, and DRI?

[Tom Horsley]

Every once in a while I try to figure out why I can't seem
to run lots of programs that want 3D (like everything
that uses GTK). They always get X errors about bad GLX
request. This is on Fedora 21 (but I had mostly the
same problems with 20 as well).

My video card is NVIDIA Corporation GM107 [GeForce GTX 750 Ti] (rev a2)
and it seems I am forced to use the rpmfusion nvidia
binary drivers because nouveau just flat doesn't work.

If I run xdpyinfo it lists GLX, DRI3, DRI2 as valid extensions,
but when I set LIBGL_DEBUG=verbose and run glxinfo
it says the screen does not appear to be DRI3 or
DRI2 capable and then also fails to load swrast.

Is this stuff supposed to be working with maxwell cards?
Is something not configured right? Is there something
a ordinary mortal can do to fix this (most of this
graphics system stuff is complete gibberish to me :-).