anchor.diff:      }
       else alternative;
   
  -  mesa_noglu = mesaDarwinOr (callPackage ../development/libraries/mesa {
  +  # FIXME: should be `libGL = libGLDarwinOr mesa_nonglu` but this change cause mass rebuild,
  +  # until all packages will refer to libGL/GLU/GLU combined
  +  mesa_noglu = libGLDarwinOr (callPackage ../development/libraries/mesa {
       # makes it slower, but during runtime we link against just mesa_drivers
       # through /run/opengl-driver*, which is overriden according to config.grsecurity
       # grsecEnabled = true; # no more support in nixpkgs ATM
     });
   
  -  mesa_glu =  mesaDarwinOr (callPackage ../development/libraries/mesa-glu { });
  -  mesa_drivers = mesaDarwinOr (
  +  mesa_glu =  libGLDarwinOr (callPackage ../development/libraries/mesa-glu { });
  +  mesa_drivers = libGLDarwinOr (
       let mo = mesa_noglu.override {
         grsecEnabled = config.grsecurity or false;
         enableTextureFloats = true;
  
positive.code:   # for packages that assume that libGLU and libGL live in the same prefix.
    # Otherwise it's better to use mesa_glu or mesa_noglu, depending on whether
    # you need libGLU or not (_glu propagates _noglu).
    mesa = mesaDarwinOr (buildEnv {
      name = "mesa-${mesa_noglu.version}";
      paths = [ mesa_noglu.dev mesa_noglu.out mesa_glu mesa_glu.dev ];
      meta = {
        platforms = lib.platforms.unix;
      };
    });
  
    meterbridge = callPackage ../applications/audio/meterbridge { };
  
  
negative.code: 
    mergerfs = callPackage ../tools/filesystems/mergerfs { };
  
    ## libGL/libGLU/Mesa stuff
  
    # Default libGL implementation, should provide headers and libGL.so/libEGL.so/... to link agains them
    # Default implementation is `mesa`, but can be eventually replaced with `libglvnd`, 
    # or other runtime dispatcher
    libGL = mesa_noglu;
  
    # Default libGLU
    libGLU = mesa_glu;
  
    # Combined derivation, contains both libGL and libGLU
    # Please, avoid using this attribute.  It was meant as transitional hack
    # for packages that assume that libGLU and libGL live in the same prefix.
    # libGLU_combined propagates both libGL and libGLU
    libGLU_combined = mesa;
  
    # Default derivation with libGL.so.1 to link into /run/opengl-drivers (if need)
    libGL_driver = mesa_drivers;
  
    mesaSupported = lib.elem system lib.platforms.mesaPlatforms;
  
    libGLDarwinOr = alternative: if stdenv.isDarwin
      then callPackage ../development/libraries/mesa-darwin {
        inherit (darwin.apple_sdk.frameworks) OpenGL;
        inherit (darwin.apple_sdk.libs) Xplugin;
  