anchor.diff:        wrapProgram $out/bin/mx \
           --prefix PATH : ${lib.makeBinPath [ python27 mercurial ]} \
           --set    FINDBUGS_HOME ${findbugs}
  -      find $out -exec touch -c -m -r '{}' --date="1980-01-01" '{}' \;
       '';
       meta = with stdenv.lib; {
         homepage = https://github.com/graalvm/mx;
  
positive.code:   jvmci8 = stdenv.mkDerivation rec {
      version = "0.49";
      name = let
               n = "jvmci8u191-${version}";
             in if (lib.stringLength n) == (lib.stringLength oraclejdk8.name) then
                  n
                else
  
negative.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 = ''
  