anchor.diff:  
         flags = mkOption {
           type = types.listOf types.str;
  -        default = [];
  -        example = [ "-I" "stuff=/home/alice/nixos-stuff" "--option" "extra-binary-caches" "http://my-cache.example.org/" ];
  +        default = [ ];
  +        example = [
  +          "-I"
  +          "stuff=/home/alice/nixos-stuff"
  +          "--option"
  +          "extra-binary-caches"
  +          "http://my-cache.example.org/"
  +        ];
           description = ''
             Any additional flags passed to <command>nixos-rebuild</command>.
  +
  +          If you are using flakes and use a local repo you can add
  +          <command>[ "--update-input" "nixpkgs" "--commit-lock-file" ]</command>
  +          to update nixpkgs.
           '';
         };
   
  
positive.code:           version. If enabled, a systemd timer will run
            <literal>nixos-rebuild switch --upgrade</literal> once a
            day.
          '';
        };
  
  
negative.code: 
  with lib;
  
  let cfg = config.system.autoUpgrade;
  
  in {
  
    options = {
  
  