anchor.diff:        };
   
         options = mkOption {
  -        type = types.str;
           default = "";
           example = "--max-freed $((64 * 1024**3))";
  +        type = types.str;
           description = ''
             Options given to <filename>nix-collect-garbage</filename> when the
             garbage collector is run automatically.
  
positive.code: in
  
  {
  
    ###### interface
  
  
negative.code:     nix.gc = {
  
        automatic = mkOption {
          default = false;
          type = types.bool;
          description = "Automatically run the garbage collector at a specific time.";
        };
  
        # Not in NixOS module
        user = mkOption {
          type = types.nullOr types.str;
          default = null;
  