So, a while back I had set up a Linux machine with an older QuadroFX video card to do some 3D stereo programming. The nVidia Linux drivers installed without a problem and everything seemed to be working. Except for the stereo part. Trying some test applications this is what I found:
With glxgears I’d get:
$ glxgears -stereo Error: couldn't get an RGB, Double-buffered, Stereo visual
With https://astronomy.swin.edu.au/~pbourke/opengl/stereogl/pulsar.c:
$ ./pulsar -s ERROR: Internal error <Visual with necessary capabilities not found> in function fgOpenWindow
Poking around the internet turned up little about this problem. However, from /usr/share/doc/NVIDIA_GLX-1.0/README.txt I found this little tid-bit: Workstation overlays, stereo visuals, and the unified back buffer (UBB) are incompatible with Composite. These features will be automatically disabled when Composite is detected. Simply running: “nvidia-xconfig --no-composite” fixed it. Looks like it added the following to xorg.conf:
Section "Extensions"
Option "Composite" "Disable"
EndSection
Hopefully this helps anyone else with this problem…