anchor.diff: -{ stdenv, fetchFromGitHub, fetchpatch, cmake, bash, gnugrep
  +{ stdenv, fetchFromGitHub, cmake, bash, gnugrep
   , fixDarwinDylibNames
   , file
   , legacySupport ? false
  
positive.code:       property shared by most LZ compression algorithms, such as zlib.
      '';
      homepage = "https://facebook.github.io/zstd/";
      license = with licenses; [ bsd3 ]; # Or, at your opinion, GPL-2.0-only.
  
      platforms = platforms.all;
  
negative.code: 
    patches = [
      ./playtests-darwin.patch
    ] # 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;
  