It seems qt6.mqtt is missing, isn't it? How do I add it to repo? overlay?

I need qt6 mqtt for my qt6 project. I cannot find mqtt in qt6 set. It seems I have to add it to repository. However, before I do I would like to ask you if qt6.mqtt is truly missing or maybe it is intentionally absent. It should be listed with other source packages at Index of /official_releases/qt/6.4/6.4.1/submodules but it is missing there too! (what is particularly important since all sources/modules come from that link)

If I were to add qt6.mqtt, how should I go about it? Can I make a flake with an overlay? Can I extend nixpkgs.qt6 set with an overlay?

It’s missing, as our update script checks the exact page you are seeing and there’s no mqtt on it. Extending a package set with a overlay can be tricky, also there’s no need to do so, just define it as a new package anywhere and it would work.

{ pkgs ? import <nixpkgs> { } }:

pkgs.qt6.callPackage
  (
    { qtModule, fetchFromGitHub, qtdeclarative, qtwebsockets }:

    qtModule rec {
      pname = "qtmqtt";
      version = "6.4.1";

      src = fetchFromGitHub {
        owner = "qt";
        repo = pname;
        rev = "v${version}";
        hash = "sha256-KCGHKxfRHpuzvKRERI6ROn+M2LPf5LTlcnd9eCUutZY=";
      };

      qtInputs = [ qtdeclarative qtwebsockets ];
    }
  )
{ }