Using nixGL to fix OpenGL applications on non-NixOS distributions

The Nix package manager can be installed on any Linux distribution, on Mac and even on Windows. I’m currently using Ubuntu 20 and am enjoying home-manager to declaratively manage my $HOME directory using Nix tooling. For instance, to use my favorite browser qutebrowser, I could just add it into my ~/.config/nixpkgs/home.nix under packages:

{ config, pkgs, ... }:

{
  home.packages = [
    pkgs.qutebrowser
  ];
}

However, since I also want to configure qutebrowser keybindings using home-manager, I’m using the builtin module instead:

{ config, pkgs, ... }:

{
  programs.qutebrowser = {
    enable = true;
    keyBindings = {
      normal = {
        "m" = "spawn mpv {url}";
      };
    };
  }
}

Then I can home-manager switch and voila, running qutebrowser on a terminal…crashes! The output is…

(process:134810): Gtk-WARNING **: 17:55:45.724: Locale not supported by C library.
        Using the fallback 'C' locale.
17:55:45 WARNING: qglx_findConfig: Failed to finding matching FBConfig for QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize -1, redBufferSize 1, greenBufferSize 1, blueBufferSize 1, alphaBufferSize -1, stencilBufferSize -1, samples -1, swapBehavior QSurfaceFormat::SingleBuffer, swapInterval 1, colorSpace QSurfaceFormat::DefaultColorSpace, profile  QSurfaceFormat::NoProfile)
17:55:45 WARNING: qglx_findConfig: Failed to finding matching FBConfig for QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize -1, redBufferSize 1, greenBufferSize 1, blueBufferSize 1, alphaBufferSize -1, stencilBufferSize -1, samples -1, swapBehavior QSurfaceFormat::SingleBuffer, swapInterval 1, colorSpace QSurfaceFormat::DefaultColorSpace, profile  QSurfaceFormat::NoProfile)
17:55:45 CRITICAL: Could not initialize GLX
Fatal Python error: Aborted

Current thread 0x00007fd65318ef80 (most recent call first):
  File "/nix/store/krj21a11r9wbw2v9dpqkgfk6zrm88a43-qutebrowser-1.14.0/lib/python3.8/site-packages/qutebrowser/app.py", line 530 in __init__
  File "/nix/store/krj21a11r9wbw2v9dpqkgfk6zrm88a43-qutebrowser-1.14.0/lib/python3.8/site-packages/qutebrowser/app.py", line 96 in run
  File "/nix/store/krj21a11r9wbw2v9dpqkgfk6zrm88a43-qutebrowser-1.14.0/lib/python3.8/site-packages/qutebrowser/qutebrowser.py", line 204 in main
  File "/nix/store/krj21a11r9wbw2v9dpqkgfk6zrm88a43-qutebrowser-1.14.0/bin/.qutebrowser-wrapped", line 9 in <module>
Aborted (core dumped)

Something about GLX?

17:55:45 CRITICAL: Could not initialize GLX

The output of glxinfo seems harmless. Is it a Nix problem, then. Let’s run:

nix-shell -p glxinfo --run glxinfo

This runs Nix’s version of glxinfo, and indeed we get:

name of display: :0
Error: couldn't find RGB GLX visual or fbconfig

The problem faced here is, sadly, known (the linked issue was opened in 2015). There is a solution, however, in the form of guibou/nixGL. I won’t go into the details of how this works and just present you with the solution. For qutebrowser, it looks like this:

{ config, pkgs, ... }:

let nixGLIntel = (pkgs.callPackage "${builtins.fetchTarball {
      url = https://github.com/guibou/nixGL/archive/17c1ec63b969472555514533569004e5f31a921f.tar.gz;
      sha256 = "0yh8zq746djazjvlspgyy1hvppaynbqrdqpgk447iygkpkp3f5qr";
    }}/nixGL.nix" {}).nixGLIntel;
in
{
  programs.qutebrowser = {
    enable = true;
    keyBindings = {
      normal = {
        "m" = "spawn mpv {url}";
      };
    };
    package =
      pkgs.writeShellScriptBin "qutebrowser" ''
           #!/bin/sh

           ${nixGLIntel}/bin/nixGLIntel ${pkgs.qutebrowser}/bin/qutebrowser "$@"
        '';
  }
}

So in the first few lines, I’m downloading a specific, pinned version of nixGL (so everything is nicely reproducible). I then wrap the qutebrowser executable inside nixGLIntel, as nixGL’s readme suggests. Then after another home-manager switch, I can execute qutebrowser without the error message.

Note that the setup is, of course, specific to me with my Intel GPU. There’s functions for NVidia and AMD, too.