{ configuration, pkgs, lib ? pkgs.lib

  # Whether to check that each option has a matching declaration.
, check ? true
  # Extra arguments passed to specialArgs.
, extraSpecialArgs ? { } }:

with lib;

let

  collectFailed = cfg:
    map (x: x.message) (filter (x: !x.assertion) cfg.assertions);

  showWarnings = res:
    let f = w: x: builtins.trace "warning: ${w}" x;
    in fold f res res.config.warnings;

  extendedLib = import ./lib/stdlib-extended.nix lib;

  hmModules = import ./modules.nix {
    inherit check pkgs;
    lib = extendedLib;
  };

  rawModule = extendedLib.evalModules {
    modules = [ configuration ] ++ hmModules;
    specialArgs = { modulesPath = builtins.toString ./.; } // extraSpecialArgs;
  };

  moduleChecks = raw:
    showWarnings (let
      failed = collectFailed raw.config;
      failedStr = concatStringsSep "\n" (map (x: "- ${x}") failed);
    in if failed == [ ] then
      raw
    else
      throw ''

        Failed assertions:
        ${failedStr}'');

  withExtraAttrs = rawModule:
    let module = moduleChecks rawModule;
    in {
      inherit (module) options config;

      activationPackage = module.config.home.activationPackage;

      # For backwards compatibility. Please use activationPackage instead.
      activation-script = module.config.home.activationPackage;

      newsDisplay = rawModule.config.news.display;
      newsEntries = sort (a: b: a.time > b.time)
        (filter (a: a.condition) rawModule.config.news.entries);

      inherit (module._module.args) pkgs;

      extendModules = args: withExtraAttrs (rawModule.extendModules args);
    };
in withExtraAttrs rawModule