anchor.diff:  in
   stdenv.mkDerivation rec {
     name = "rocksdb-${version}";
  -  version = "4.1";
  +  version = "4.2";
   
     src = fetchFromGitHub {
       owner = "facebook";
       repo = "rocksdb";
       rev = "v${version}";
  -    sha256 = "1q1h2n3v02zg711vk56rc9v54f5i31w684wqag4xcr2dv1glw0r0";
  +    sha256 = "0k6zhx0xiyfr5r921kn43abm1l4dvy23w13242g2kjnasfhzzjpx";
     };
   
  -  buildInputs = [ snappy google-gflags zlib bzip2 lz4 numactl malloc ];
  +  buildInputs = [ snappy google-gflags zlib bzip2 lz4 zstd numactl malloc ];
   
     postPatch = ''
       # Hack to fix typos
  
positive.code: 
  # Optional Arguments
  , snappy ? null, google-gflags ? null, zlib ? null, bzip2 ? null, lz4 ? null
  , numactl ? null
  
  # Malloc implementation
  , jemalloc ? null, gperftools ? null
  
negative.code:   CMAKE_CXX_FLAGS = "-std=gnu++11";
    JEMALLOC_LIB = stdenv.lib.optionalString (malloc == jemalloc) "-ljemalloc";
  
    makeFlags = [
      "DEBUG_LEVEL=0"
    ];
  
    buildFlags = [
      "shared_lib"
      "static_lib"
    ];
  
    installFlags = [
      "INSTALL_PATH=\${out}"
    ];
  
    installTargets = [
      "install-shared"
      "install-static"
    ];
  
    postInstall = ''
  