anchor.diff:    void _update() {
       if (log.isMuted) return;
   
  -    stdout.write(log.format("\r$_message... "));
  -
       // Show the time only once it gets noticeably long.
  -    if (_stopwatch.elapsed.inSeconds > 0) stdout.write("${log.gray(_time)} ");
  +    if (_stopwatch.elapsed.inSeconds > 0) {
  +      String backspace = "\b" * _timeLength;
  +      String time = "${log.gray(_time)} ";
  +      _timeLength = time.length;
  +      stdout.write("$backspace$time");
  +    }
     }
   }
  
positive.code: 
      // Print a final message without a time indicator so that we don't leave a
      // misleading half-complete time indicator on the console.
      stdout.writeln(log.format("\r$_message..."));
      _timer.cancel();
      _timer = null;
    }
  
negative.code: 
    /// Gets the current progress time as a parenthesized, formatted string.
    String get _time => "(${niceDuration(_stopwatch.elapsed)})";
  
    /// Last printed time length
    int _timeLength = 0;
  
    /// Creates a new progress indicator.
    ///
  