anchor.diff:  
         tcp = {
           port = mkOption {
  +          type = types.port;
             default = 2086;  # assigned by IANA
             description = ''
               The TCP port for use by GNUnet.
  
positive.code:       };
  
        extraOptions = mkOption {
          default = "";
          description = ''
            Additional options that will be copied verbatim in `gnunet.conf'.
  
negative.code: 
        udp = {
          port = mkOption {
            type = types.port;
            default = 2086;  # assigned by IANA
            description = ''
              The UDP port for use by GNUnet.
  