anchor.diff:            ) | ${pkgs.postgresql}/bin/psql -U "${config.dbUser}" "${config.dbName}"
         fi
       '');
  -    
  +
  +  robotsEntries = optionalString (config.articleUrlPrefix != "")
  +    ''
  +      User-agent: *
  +      Disallow: ${config.urlPrefix}/
  +      Disallow: ${config.articleUrlPrefix}/Special:Search
  +      Disallow: ${config.articleUrlPrefix}/Special:Random
  +    '';
  +
   }
  
positive.code: 
          $wgSitename = "${config.siteName}";
  
          ${config.extraConfig}
        ?>
      '';
  
negative.code:       description = "Name of the wiki";
      };
  
      logo = mkOption {
        default = "";
        example = "/images/logo.png";
        description = "The URL of the site's logo (which should be a 135x135px image).";
      };
  
      urlPrefix = mkOption {
        default = "/w";
        description = ''
          The URL prefix under which the Mediawiki service appears.
        '';
      };
  
      articleUrlPrefix = mkOption {
        default = "/wiki";
        example = "";
        description = ''
          The URL prefix under which article pages appear,
          e.g. http://server/wiki/Page.  Leave empty to use the main URL
          prefix, e.g. http://server/w/index.php?title=Page.
        '';
      };
  
  