anchor.diff:  { stdenv
  -, fetchgit
  -, fetchurl
  +, fetchFromGitLab
   , lib
   , nasm
   }:
  
positive.code: # NOTE: the videolan autogenerated tarballs do not contain the latest sources.
  
  let
    version = "2018-09-25";
  in
  stdenv.mkDerivation rec {
    name = "x264-${version}";
  
    src = fetchurl {
      url = "http://x264-${version}.tar.xz";
      multihash = "QmP94FLFCDNDBDx9SFPEgnmPQ1jKvt3hvNmFjkN2uot9Gm";
      sha256 = "a47d528a9e2e077aa820418b57c3c718d17c681fa9360e3a5526955e406ae0e5";
    };
  
    nativeBuildInputs = [
  
negative.code:     "--disable-lsmash"
    ];
  
    meta = with lib; {
      description = "Library for encoding h.264/AVC video streams";
      homepage = https://www.videolan.org/developers/x264.html;
  