{ config, lib, pkgs, ... }:

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

    settings = {
      auto-optimise-store = true;
      experimental-features = [ "nix-command" "flakes" "repl-flake" ];
      warn-dirty = false;

      # avoid unwanted garbage collection when using direnv
      keep-outputs = true;
      keep-derivations = true;
    };
  };
}