anchor.diff:  }:
   
   let
  -  version = "2.23";
  +  version = "2017-11-21";
   in
   stdenv.mkDerivation rec {
     name = "ffms-${version}";
   
  -  src = fetchzip {
  -    version = 2;
  -    url = "https://github.com/FFMS/ffms2/archive/${version}.tar.gz";
  -    sha256 = "8a40f22a28e15c974906a222b44b6df29d9c50d34f41ded1ab1ad6edd6711a8d";
  +  src = fetchFromGitHub {
  +    version = 4;
  +    owner = "ffms";
  +    repo = "ffms2";
  +    rev = "c71cade921072bce46289635ed0780e5ce01beab";
  +    sha256 = "3cddcca60423fa7ba0b293e888632b541940ac63a4e14a3703acfa6f904aab77";
     };
   
     nativeBuildInputs = [
  
positive.code:     ffmpeg
      zlib
    ];
  
    configureFlags = [
      "--disable-debug"
  
negative.code: { stdenv
  , autoreconfHook
  , fetchFromGitHub
  , lib
  
  , ffmpeg
  