{ pkgs ? import (builtins.fetchTarball {
    url = "https://github.com/NixOS/nixpkgs/archive/master.tar.gz";
  }) {}
}:

let
  ocamlPackages = pkgs.ocaml-ng.ocamlPackages_5_4.overrideScope (self: super: {
    htmlit = ocamlPackages.buildTopkgPackage rec {
      pname = "htmlit";
      version = "0.2.0";

      minimalOCamlVersion = "4.14.0";

      src = pkgs.fetchzip {
        url = "https://erratique.ch/software/htmlit/releases/htmlit-${version}.tbz";
        hash = "sha256-vE6XY7INMCwQztZqKhJaxpNF0o5+NeutJM5XobshClE=";
      };
    };
  });
in

pkgs.mkShell {
  nativeBuildInputs = with ocamlPackages; [
    dune_3
    findlib
    merlin
    ocaml
    ocamlformat
    odoc
  ];
  buildInputs = with ocamlPackages; [
    httpcats
    js_of_ocaml-compiler
    miou
    ptime
    htmlit
    scfg
    tyxml
    uri
    uuidm
    directories
  ];
}