The Case of the Broken OpenGL Extensions

Like a good boy I did my apt-get update / apt-get upgrade the other day and thought everything was ok.  It pulled down some updates and a new nvidia-current (yes, running Ubuntu with some development ppa’s).  Upon rebooting I noticed compositing in kwin had stopped.  I thought maybe the sequence of updates had messed something up because there was one xorg update that came in after nvidia-current. 

So I ran glxinfo and log and behold I had no GL extensions whatsoever.  Hrm, this is a problem I thought.  I also ran nvidia-settings to see what it said and the OpenGL tab also said nothing was there.  Did a quick web check and no one else was reporting problems with the version of the nvidia driver I had.

I then did a quick ldd `which glxinfo` to see what was up, thinking that one of the xorg updates might have sneaked in some mesa configs.  Sure enough, glxinfo was pulling from mesa instead of the nvidia binary.  I looked in /etc/ and found a i386-linux-gnu_GL.conf file that indeed placed mesa in ldconfig’s path higher than the nvidia one.  A quick rm i386-linux-gnu_GL.conf and restarting of X fixed things.

The moral of the story is, if you’re like me and have the xorg edgers ppa installed and have suddenly lost OpenGL acceleration, check your /etc/ dir.