anchor.diff:  
     createFindlibDestdir = true;
   
  -  postPatch = ''
  -    substituteInPlace src/reasonbuild/myocamlbuild.ml \
  -      --replace "refmt --print binary" "$out/bin/refmt --print binary"
  -  '';
  -
     installPhase = ''
  -    ${jbuilder.installPhase}
  +    for p in reason rtop
  +    do
  +      ${jbuilder.installPhase} $p.install
  +    done
   
       wrapProgram $out/bin/rtop \
         --prefix PATH : "${utop}/bin" \
  
positive.code: 
  buildOcaml rec {
    name = "reason";
    version = "3.0.4";
  
    src = fetchFromGitHub {
      owner = "facebook";
      repo = "reason";
      rev = version;
      sha256 = "15qhx85him5rr4j0ygj3jh3qv9ijrn82ibr9scbn0qrnn43kj047";
    };
  
    propagatedBuildInputs = [ menhir merlin_extend ppx_tools_versioned ];
  
negative.code:   meta = with stdenv.lib; {
      homepage = https://reasonml.github.io/;
      description = "Facebook's friendly syntax to OCaml";
      license = licenses.mit;
      maintainers = [ maintainers.volth ];
    };
  }
  