anchor.diff:  
     patches = [
       ./playtests-darwin.patch
  -    (fetchpatch {
  -      url = "https://github.com/facebook/zstd/pull/2163.patch";
  -      sha256 = "07mfjc5f9wy0w2xlj36hyf7g5ax9r2rf6ixhkffhnwc6rwy0q54p";
  -    })
     ] # This I didn't upstream because if you use posix threads with MinGW it will
       # work fine, and I'm not sure how to write the condition.
       ++ stdenv.lib.optional stdenv.hostPlatform.isWindows ./mcfgthreads-no-pthread.patch;
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "zstd";
    version = "1.4.5";
  
    src = fetchFromGitHub {
      owner = "facebook";
      repo = "zstd";
      rev = "v${version}";
      sha256 = "0ay3qlk4sffnmcl3b34q4zd7mkcmjds023icmib1mdli97qcp38l";
    };
  
    nativeBuildInputs = [ cmake ]
  
negative.code:       property shared by most LZ compression algorithms, such as zlib.
      '';
      homepage = "https://facebook.github.io/zstd/";
      changelog = "https://github.com/facebook/zstd/blob/v${version}/CHANGELOG";
      license = with licenses; [ bsd3 ]; # Or, at your opinion, GPL-2.0-only.
  
      platforms = platforms.all;
  