{
  pkgs,
  lib,
  config,
  ...
}: {
  # Allow unfree packages
  nixpkgs.config.allowUnfree = true; # TODO: replace this with allowUnfreePredicate

  # enable nix flakes
  nix.settings.experimental-features = ["nix-command" "flakes"];

  nix.settings.trusted-users = ["root" "osbm"];

  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 30d";
  };

  # nix.nixPath = ["nixpkgs=${pkgs.path}"];

  # disable the database error TODO add nix-index search
  programs.command-not-found.enable = false;
}