anchor.diff:        --replace "zstdcat" "$bin/bin/zstdcat"
     '' + lib.optionalString stdenv.isDarwin ''
       install_name_tool -change @rpath/libzstd.1.dylib $out/lib/libzstd.1.dylib $bin/bin/pzstd
  +  '' + lib.optionalString buildContrib ''
  +    cp contrib/pzstd/pzstd $bin/bin/pzstd
     '';
   
     outputs = [ "bin" "dev" ]
  
positive.code: 
    preInstall = ''
      mkdir -p $bin/bin
      cp contrib/pzstd/pzstd $bin/bin/pzstd
      substituteInPlace ../programs/zstdgrep \
        --replace ":-grep" ":-${gnugrep}/bin/grep" \
        --replace ":-zstdcat" ":-$bin/bin/zstdcat"
  
negative.code:   '';
  
    checkInputs = [ file ];
    inherit doCheck;
    checkPhase = ''
      runHook preCheck
      # Patch shebangs for playTests
  