anchor.diff:        if (responses.haveGarbage()) {
           error("Error: leftover text after message: '${responses.buffer}'");
           error("Previous message may be malformed, was: '$msg'");
  -        close(killDebugee: true);
  +        cleanup();
           return;
         }
         var msgObj = JSON.parse(msg);
  
positive.code:   int seqNr = 0;  // Sequence number of next debugger command message.
    Command lastCommand = null;  // Most recent command sent to target.
    List<String> errors = new List();
  
    // Data collected from debug target.
    Map currentMessage = null;  // Currently handled message sent by target.
  
negative.code:       }
      }
      if (frames.length < functionNames.length) {
        debugger.error("Error: stack trace not long enough "
                       "to match ${functionNames.length} frames");
        return;
      }
  