{ config, pkgs, ... }:
let
  unstableTarball = fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz;
in
  {
    nixpkgs.config = {
      packageOverrides = pkgs: {
        unstable = import unstableTarball {
          config = config.nixpkgs.config;
        };
      };
    };
    virtualisation.virtualbox.host = {
      enable = true;
      enableExtensionPack = true;
      enableHardening = false;
    };
  }