Getting an error, has anything regarding OpenGL in nixpkgs?

pimiddy · August 7, 2019, 6:47am

Since updating yesterday, I cannot start my OpenGL application anymore. GL initialization seems to fail, although I cannot get an error message just yet, so I’m asking very generally: Has anything changed in regard to OpenGL library handling in nixpkgs? I’m noticing that LD_LIBRARY_PATH seems a bit smaller now.

vcunat · August 7, 2019, 10:21am

IIRC some older nixpkgs builds might stop finding GL libs without LD_LIBRARY_PATH. Relatively recent builds should be OK.

matthewbauer · August 8, 2019, 2:59pm

Hmmm… perhaps we got rid of the LD_LIBRARY_PATH paths a little bit too early. It will mean you can’t use pre-19.09 GL apps on NixOS 19.09. It’s not too hard to get into this situation if you utilize pinning in your projects. I would propose making hardware.opengl.setLdLibraryPath true for 19.09 and maybe planning to change the default to false for 20.03.

There is an option you can set manually:

github.com

NixOS/nixpkgs/blob/7803ff314c707ee11a6d8d1c9ac4cde70737d22e/nixos/modules/hardware/opengl.nix#L125


      
              description = ''
                Additional packages to add to 32-bit OpenGL drivers on
                64-bit systems. Used when <option>driSupport32Bit</option> is
                set. This can be used to add OpenCL drivers, VA-API/VDPAU drivers etc.
              '';
            };
          
          
  setLdLibraryPath = mkOption {
              type = types.bool;
              internal = true;
              default = false;
              description = ''
                Whether the <literal>LD_LIBRARY_PATH</literal> environment variable
                should be set to the locations of driver libraries. Drivers which
                rely on overriding libraries should set this to true. Drivers which
                support <literal>libglvnd</literal> and other dispatch libraries
                instead of overriding libraries should not set this.
              '';
            };
          };

vcunat · August 9, 2019, 1:53pm

I thought the nixpkgs had to be much older for GL to break, somewhere when we switched to linking against libglvnd stubs – and only the OS-level stuff like drivers needed the later work. (@ambrop72 might remember but apparently isn’t on this forum)

worldofpeace · September 15, 2019, 9:49pm

Just a heads up to users on unstable where this is still disabled, you can use the following:

hardware.opengl.setLdLibraryPath = true;

to get the old behavior.

If you plan to use the upcoming 19.09 release the change has been reverted there, so the aforementioned should be unneeded.

NilsIrl · October 19, 2019, 4:04pm

I seem to have this problem on 19.09