nixpkgs/pkgs/tools/X11/primus/default.nix

# For a 64bit + 32bit system the LD_LIBRARY_PATH must contain both the 32bit and 64bit primus
# libraries. Providing a different primusrun for each architecture will not work as expected. EG:
# Using steam under wine can involve both 32bit and 64bit process. All of which inherit the
# same LD_LIBRARY_PATH.
# Other distributions do the same.
{ stdenv
, stdenv_i686
, lib
, primusLib
, writeScriptBin
, primusLib_i686 ? null
, useNvidia ? true
}:

let
  # We override stdenv in case we need different ABI for libGL
  primusLib_ = primusLib.override { inherit stdenv; };
  primusLib_i686_ = primusLib_i686.override { stdenv = stdenv_i686; };

  primus = if useNvidia then primusLib_ else primusLib_.override { nvidia_x11 = null; };
  primus_i686 = if useNvidia then primusLib_i686_ else primusLib_i686_.override { nvidia_x11 = null; };
  ldPath = lib.makeLibraryPath (lib.filter (x: x != null) (
    [ primus primus.glvnd ]
    ++ lib.optionals (primusLib_i686 != null) [ primus_i686 primus_i686.glvnd ]
  ));

in writeScriptBin "primusrun" ''
  #!${stdenv.shell}
  export LD_LIBRARY_PATH=${ldPath}:$LD_LIBRARY_PATH
  exec "$@"
''