anchor.diff:        owner  = "oracle";
         repo   = "graal";
         rev    = "vm-${version}";
  -      sha256 = "1hcs4m6ailapgi3bikav1i517vqn5pn595cyqqjfvlnkjwihbnc3";
  +      sha256 = "1fada4awrr8bhw294xdiq4bagvgrlcr44mw6338gaal0ky3vkm0p";
       };
       buildInputs = [ mx zlib mercurial jvmci8 ];
       postUnpack = ''
  
positive.code: 
        export MX_ALT_OUTPUT_ROOT=$NIX_BUILD_TOP/mxbuild
        export MX_CACHE_DIR=${makeMxCache jvmci8-mxcache}
        mx --java-home $(pwd)/writable-copy-of-jdk build
      '';
      installPhase = ''
  
negative.code: in rec {
  
    mx = stdenv.mkDerivation rec {
      version = "5.192.0";
      name = "mx";
      src = fetchFromGitHub {
        owner  = "graalvm";
        repo   = "mx";
        rev    = version;
        sha256 = "04gdf1gzlc8a6li8lcnrs2j9zicj11fs1vqqf7cmhb4pm2h72hml";
      };
      nativeBuildInputs = [ makeWrapper ];
      buildPhase = ''
  