anchor.diff:  
   stdenv.mkDerivation {
   
  -  name = "camlp5${if transitional then "_transitional" else ""}-6.16";
  +  name = "camlp5${if transitional then "_transitional" else ""}-6.17";
   
  -  src = fetchurl {
  -    url = http://camlp5.gforge.inria.fr/distrib/src/camlp5-6.16.tgz;
  -    sha256 = "1caqa2rl7rav7pfwv1l1j0j18yr1qzyyqz0wa9519x91ckznqi7x";
  +  src = fetchzip {
  +    url = https://github.com/camlp5/camlp5/archive/rel617.tar.gz;
  +    sha256 = "0finmr6y0lyd7mnl61kmvwd32cmmf64m245vdh1iy0139rxf814c";
     };
   
     buildInputs = [ ocaml ];
  
positive.code: {stdenv, fetchurl, ocaml, transitional ? false}:
  
  let
    metafile = ./META;
  
negative.code:       Camlp5 is a preprocessor and pretty-printer for OCaml programs.
        It also provides parsing and printing tools.
      '';
      homepage = https://camlp5.github.io/;
      license = licenses.bsd3;
      platforms = ocaml.meta.platforms or [];
      maintainers = with maintainers; [
  