{ config, pkgs, ... }:
{

##### nix extra options #######

  nix = {
    extraOptions = ''
      experimental-features = nix-command flakes	
      keep-outputs = true
      keep-derivations = true
    '';
#    package = pkgs.nixFlakes;
    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 7d";
      persistent = true;
    };
    settings.auto-optimize-store = true;
  };
}

}