nix/nixos/common/modules/nixos.nix

{ pkgs, system, stateVersion, ... }: { 
  nix = {
    settings = {
      auto-optimise-store = true;
      experimental-features = [ "nix-command"  "flakes" ];
    };
    optimise = {
      automatic = true;
      dates = [ "daily" ];
    };
    gc = {
      automatic = true;
      dates = "daily";
      options = "--delete-older-than 30d";
    };
  };

  # Select internationalisation properties.
  i18n.defaultLocale = "en_US.UTF-8";
  i18n.extraLocaleSettings = {
    LC_ADDRESS = "en_US.UTF-8";
    LC_IDENTIFICATION = "en_US.UTF-8";
    LC_MEASUREMENT = "en_US.UTF-8";
    LC_MONETARY = "en_US.UTF-8";
    LC_NAME = "en_US.UTF-8";
    LC_NUMERIC = "en_US.UTF-8";
    LC_PAPER = "en_US.UTF-8";
    LC_TELEPHONE = "en_US.UTF-8";
    LC_TIME = "en_US.UTF-8";
  };

  # https://github.com/NixOS/nixpkgs/issues/180175#issuecomment-1658731959
  systemd.services.NetworkManager-wait-online = {
    serviceConfig = {
      ExecStart = [ "" "${pkgs.networkmanager}/bin/nm-online -q" ];
    };
  };

  system.stateVersion = stateVersion;
  nixpkgs.hostPlatform = system;
}