anchor.diff:          hg checkout ${lib.escapeShellArg src.rev}
         )
       '';
  +    hardeningDisable = [ "fortify" ];
       NIX_CFLAGS_COMPILE = [
         "-Wno-error=format-overflow" # newly detected by gcc7
  +      "-Wno-error=nonnull"
       ];
       buildPhase = ''
         cp -dpR ${oraclejdk8} writable-copy-of-jdk
  
positive.code:     src = fetchFromGitHub {
        owner  = "oracle";
        repo   = "graal";
        rev    = "vm-enterprise-${version}";
        sha256 = "0rhd6dk2jpbxgdprqvdk991b2k177jrjgyjabdnmv5lzlhczy676";
      };
      buildInputs = [ mx zlib mercurial jvmci8 ];
      postUnpack = ''
  
negative.code: 
    # copy of pkgs.oraclejvm8 with JVMCI interface (TODO: it should work with pkgs.openjdk8 too)
    jvmci8 = stdenv.mkDerivation rec {
      version = "0.43";
      name = let
               n = "jvmci8u171-${version}";
             in if (lib.stringLength n) == (lib.stringLength oraclejdk8.name) then
                  n
                else
  