{ config, pkgs, ...}:
{
  environment.systemPackages = [
    (emacsWithPackagesFromUsePackage {
      # Your Emacs config file. Org mode babel files are also
      # supported.
      # NB: Config files cannot contain unicode characters, since
      #     they're being parsed in nix, which lacks unicode
      #     support.
      # config = ./emacs.org;
      config = ./default.el;

      # Package is optional, defaults to pkgs.emacs
      package = pkgs.emacsGit;

      # By default emacsWithPackagesFromUsePackage will only pull in
      # packages with `:ensure`, `:ensure t` or `:ensure <package name>`.
      # Setting `alwaysEnsure` to `true` emulates `use-package-always-ensure`
      # and pulls in all use-package references not explicitly disabled via
      # `:ensure nil` or `:disabled`.
      # Note that this is NOT recommended unless you've actually set
      # `use-package-always-ensure` to `t` in your config.
      alwaysEnsure = true;

      # For Org mode babel files, by default only code blocks with
      # `:tangle yes` are considered. Setting `alwaysTangle` to `true`
      # will include all code blocks missing the `:tangle` argument,
      # defaulting it to `yes`.
      # Note that this is NOT recommended unless you have something like
      # `#+PROPERTY: header-args:emacs-lisp :tangle yes` in your config,
      # which defaults `:tangle` to `yes`.
      alwaysTangle = true;

      # Optionally provide extra packages not in the configuration file.
      extraEmacsPackages = epkgs: [
        epkgs.cask
      ];

      # Optionally override derivations.
      override = epkgs: epkgs // {
        weechat = epkgs.melpaPackages.weechat.overrideAttrs(old: {
          patches = [ ./weechat-el.patch ];
        });
      };
    })
  ];
}