anchor.diff:  }:
   
   let
  -  version = "19.0.2";
  +  version = "19.1.0";
     truffleMake = ./truffle.make;
     R = fetchurl {
       url = "http://cran.rstudio.com/src/base/R-3/R-3.5.1.tar.gz";
  
positive.code: in rec {
  
    mx = stdenv.mkDerivation rec {
      version = "5.224.1";
      pname = "mx";
      src = fetchFromGitHub {
        owner  = "graalvm";
        repo   = "mx";
        rev    = version;
        sha256 = "1gf8fbzn6mfg3p71mxx89ks4n6zlr6ia9zj2sq0dflp4aa0acx6q";
      };
      nativeBuildInputs = [ makeWrapper ];
      prePatch = ''
  
negative.code:   };
  
    jvmci8 = stdenv.mkDerivation rec {
      version = "20-b04";
      name = "jvmci-${version}";
      src = fetchFromGitHub {
        owner  = "graalvm";
        repo   = "graal-jvmci-8";
        rev    = "jvmci-${version}";
        sha256 = "1k9szvnl5j3vg645si7s9lb93bkfl4ifc2z8ngnlb23ircsn3qdx";
      };
      buildInputs = [ mx mercurial openjdk ];
      postUnpack = ''
  