anchor.diff:        python3
       ];
   
  -    patchPhase = ''
  -      mkdir -p glad/include/KHR
  -
  -      cp ${gl} glad/gl.xml
  -      cp ${egl} glad/include/KHR/khrplatform.h
  -      patchShebangs .
  +    preConfigure = ''
  +      export CFLAGS="-march=native"
       '';
   
       makeFlags = optional (!enableGlfw) "DISABLE_GLFW=1";
  
positive.code: 
  let
    inherit (stdenv.lib) optional makeLibraryPath;
  
    # gl.xml
    gl = fetchurl {
      url = https://raw.githubusercontent.com/KhronosGroup/OpenGL-Registry/56312cfe680e4be5ae61bbf1c628e420f8731718/xml/gl.xml;
      sha256 = "1c45bcgaxiic5gmb3gkrd9qcvascvij97vz5y6fc3a2y7x3gjc5l";
    };
    # EGL 1.5
    egl = fetchurl {
      url = https://www.khronos.org/registry/EGL/api/KHR/khrplatform.h;
      sha256 = "0p0vs4siiya05cvbqq7cw3ci2zvvlfh8kycgm9k9cwvmrkj08349";
    };
  
    wrapperScript = writeScript "glava" ''
      #!${stdenv.shell}
  
negative.code: in
    stdenv.mkDerivation rec {
      name = "glava-${version}";
      version = "1.5.5";
  
      src = fetchgit {
        url = "https://github.com/wacossusca34/glava.git";
        rev = "v${version}";
        sha256 = "0mpbgllwz45wkax6pgvnh1pz2q4yvbzq2l8z8kff13wrsdvl8lh0";
      };
  
      buildInputs = [
  