anchor.diff: -{ stdenv, fetchurl, ocaml }:
  +{ stdenv, fetchurl, ocamlPackages }:
   
   stdenv.mkDerivation rec {
     name = "hevea-2.29";
  
positive.code:     homepage = http://pauillac.inria.fr/~maranget/hevea/;
      license = licenses.qpl;
      maintainers = with maintainers; [ pSub ];
      platforms = with platforms; linux;
    };
  }
  
negative.code:     sha256 = "1i7qkar6gjpsxqgdm90xxgp15z7gfyja0rn62n23a9aahc0hpgq6";
    };
  
    buildInputs = with ocamlPackages; [ ocaml ocamlbuild ];
  
    makeFlags = "PREFIX=$(out)";
  
  