anchor.diff:      ];
   
       patchPhase = ''
  -      cp -r --no-preserve=all ${glad}/* glad
         mkdir -p glad/include/KHR
   
         cp ${gl} glad/gl.xml
  
positive.code: { stdenv, fetchurl, writeScript, fetchFromGitHub
  , libGL, libX11, libXext, python3, libXrandr, libXrender, libpulseaudio, libXcomposite
  , enableGlfw ? false, glfw }:
  
  let
    inherit (stdenv.lib) optional makeLibraryPath;
  
    version = "1.4.5";
    gladVersion = "0.1.24";
    # glad
    # https://github.com/wacossusca34/glava/issues/46#issuecomment-397816520
    glad = fetchFromGitHub {
      owner = "Dav1dde";
      repo = "glad";
      rev = "v${gladVersion}";
      sha256 = "0s2c9w064kqa5i07w8zmvgpg1pa3wj86l1nhgw7w56cjhq7cf8h8";
    };
    # gl.xml
    gl = fetchurl {
      url = https://raw.githubusercontent.com/KhronosGroup/OpenGL-Registry/a24f3f7a4c924fdbc666024f99c70e5b8e34c819/xml/gl.xml;
      sha256 = "1mskxjmhb35m8qv255pibf633d8sn1w9rdsf0lj75bhlgy0zi5c7";
    };
    # EGL 1.5
    egl = fetchurl {
  
negative.code: in
    stdenv.mkDerivation rec {
      name = "glava-${version}";
      version = "1.5.1";
  
      src = fetchgit {
        url = "https://github.com/wacossusca34/glava.git";
        rev = "v${version}";
        sha256 = "1k8x0a0g2pm7ficsk4az9s7mjbm85a987apjg5c4y6iyldxgd6sb";
      };
  
      buildInputs = [
  