anchor.diff:  
     outputs = [ "out" "dev" "bin" ];
   
  -  nativeBuildInputs = [ pkgconfig ];
  +  nativeBuildInputs = [ pkgconfig meson ninja ];
     buildInputs = [ libpthreadstubs libpciaccess valgrind-light ];
  -    # libdrm as of 2.4.70 does not actually do anything with udev.
   
     postPatch = ''
       for a in */*-symbol-check ; do
  
positive.code: { stdenv, fetchurl, pkgconfig, libpthreadstubs, libpciaccess, valgrind-light }:
  
  stdenv.mkDerivation rec {
    name = "libdrm-2.4.98";
  
negative.code:     done
    '';
  
    mesonFlags =
      [ "-Dinstall-test-programs=true" ]
      ++ stdenv.lib.optionals (stdenv.isAarch32 || stdenv.isAarch64)
        [ "-Dtegra=true" "-Detnaviv=true" ]
      ++ stdenv.lib.optional (stdenv.hostPlatform != stdenv.buildPlatform) "-Dintel=false"
      ;
  
    enableParallelBuilding = true;
  
    meta = {
      homepage = https://dri.freedesktop.org/libdrm/;
  