Using overlays to override package options -- Emacs

Hello!

I’ve been trying to use an overlay to configure set some Emacs build
options – dropping GTK3 in favor of GTK2/Athena. In doing so, no build
that I’ve had has done so. How can I go about doing so?

Current overlay is as follows:

self: super: {
  emacs = super.emacs.override {
    withGTK2 = false;
    withGTK3 = false;
    withXwidgets = false;
    withX = true;
  };
}

Any and all help is appreciated.

Thanks,

Sam