Also got these to not compile gtk and some other packages

  nixpkgs.overlays = [
    (final: prev: {
      stoken = prev.stoken.override { withGTK3 = false; };
      alsa-utils = prev.alsa-utils.override {
        withPipewireLib = false;
        fftw = null;
      };
      alsa-plugins = prev.alsa-plugins.override {
        libpulseaudio = null;
        speexdsp = null;
      };
      sdl2 = prev.sdl2.override {
        pipewireSupport = false;
        pulseaudioSupport = false;
        x11Support = false;
        jackSupport = false;
      };
      ffmpeg = prev.ffmpeg_7-headless.override {
        withSpeex = false;
        withOpenmpt = false;
      };
    })
  ];

eb:

(
  { config, pkgs, ... }:
  {
    options.nixpkgsNative.pkgs = lib.mkOption {
      type = lib.types.pkgs;
      default = null;
      description = "Native nixpkgs for the system being cross-compiled to get native packages to reduce build amounts";
    };
                                                                                                                         
    config.nixpkgsNative.pkgs = import pkgs.path {
      localSystem = config.nixpkgs.crossSystem;
      inherit (config.nixpkgs) crossSystem config;
    };
                                                                                                                         
  }
)

config.nixpkgsNative.pkgs.mpv-unwrapped

Nice, ty.

I did a similar thing to avoid specialArgs, but with pkgs.unstable as an overlay for nixpkgs-unstable when I needed it downstream for other reasons.

Broader plan is to be able to cross-compile hello for macOS from Linux

is that huh feasible? I thought building for macos required all sorts of proprietary/legal shenanigans