anchor.diff:      rm $out/lib/*.a
     '';
   
  -  nativeBuildInputs = [ cmake yasm ];
  +  nativeBuildInputs = [ cmake nasm ] ++ stdenv.lib.optional numaSupport numactl;
   
     meta = with stdenv.lib; {
       description = "Library for encoding h.265/HEVC video streams";
  
positive.code: 
  stdenv.mkDerivation rec {
    name = "x265-${version}";
    version = "2.9";
  
    src = fetchurl {
      urls = [
        "https://get.videolan.org/x265/x265_${version}.tar.gz"
        "ftp://ftp.videolan.org/pub/videolan/x265/x265_${version}.tar.gz"
      ];
      sha256 = "090hp4216isis8q5gb7bwzia8rfyzni54z21jnwm97x3hiy6ibpb";
    };
  
    enableParallelBuilding = true;
  
    patches = [
      # Fix issue #442 (linking issue on non-x86 platforms)
      # Applies on v2.9 only, this should be removed at next update
      (fetchpatch {
        url = "https://bitbucket.org/multicoreware/x265/commits/471726d3a0462739ff8e3518eb1a1e8a01de4e8d/raw";
        sha256 = "0mj8lb8ng8lrhzjavap06vjhqf6j0r3sn76c6rhs3012f86lv928";
      })
      # Fix build on ARM (#406) 
      (fetchpatch {
        url = "https://bitbucket.org/multicoreware/x265/issues/attachments/406/multicoreware/x265/1527562952.26/406/X265-2.8-asm-primitives.patch";
        sha256 = "1vf8bpl37gbd9dcbassgkq9i0rp24qm3bl6hx9zv325174bn402v";
  
negative.code: { stdenv, fetchurl, fetchpatch, cmake, nasm, numactl
  , numaSupport ? stdenv.hostPlatform.isLinux && (stdenv.hostPlatform.isx86 || stdenv.hostPlatform.isAarch64)  # Enabled by default on NUMA platforms
  , debugSupport ? false # Run-time sanity checks (debugging)
  , highbitdepthSupport ? false # false=8bits per channel, true=10/12bits per channel
  , werrorSupport ? false # Warnings as errors
  