anchor.diff:  
     meta = {
       homepage = "https://github.com/ocaml-community/sedlex";
  +    changelog = "https://github.com/ocaml-community/sedlex/raw/v${version}/CHANGES";
       description = "An OCaml lexer generator for Unicode";
       license = lib.licenses.mit;
       maintainers = [ lib.maintainers.marsam ];
  
positive.code: in
  buildDunePackage rec {
    pname = "sedlex";
    version = "2.2";
  
    useDune2 = true;
  
  
negative.code:     owner = "ocaml-community";
      repo = "sedlex";
      rev = "v${version}";
      sha256 = "0iw3phlaqr27jdf857hmj5v5hdl0vngbb2h37p2ll18sw991fxar";
    };
  
    propagatedBuildInputs = [
      gen uchar ppxlib
    ];
  
    preBuild = ''
  