anchor.diff:        Camlp5 is a preprocessor and pretty-printer for OCaml programs.
         It also provides parsing and printing tools.
       '';
  -    homepage = http://pauillac.inria.fr/~ddr/camlp5/;
  +    homepage = https://camlp5.github.io/;
       license = licenses.bsd3;
       platforms = ocaml.meta.platforms or [];
       maintainers = with maintainers; [
  
positive.code: {stdenv, fetchurl, ocaml, transitional ? false}:
  
  let
    metafile = ./META;
  
negative.code: 
  stdenv.mkDerivation {
  
    name = "camlp5${if transitional then "_transitional" else ""}-6.17";
  
    src = fetchzip {
      url = https://github.com/camlp5/camlp5/archive/rel617.tar.gz;
      sha256 = "0finmr6y0lyd7mnl61kmvwd32cmmf64m245vdh1iy0139rxf814c";
    };
  
    buildInputs = [ ocaml ];
  