Bad state: StreamSink is bound to a stream

[kkazuo]

import 'dart:io';

main() {
  stdout
    ..writeln('hello')
    ..flush() // <-- ?
    ..writeln('world');
}

% dart --version

Dart SDK version: 2.17.5 (stable) (Tue Jun 21 11:05:10 2022 +0200) on "macos_x64"

% dart /tmp/a.dart

hello
Unhandled exception:
Bad state: StreamSink is bound to a stream
#0      _StreamSinkImpl._controller (dart:io/io_sink.dart:216:7)
#1      _StreamSinkImpl.add (dart:io/io_sink.dart:136:5)
#2      _IOSinkImpl.write (dart:io/io_sink.dart:269:5)
#3      _IOSinkImpl.writeln (dart:io/io_sink.dart:289:5)
#4      _StdSink.writeln (dart:io/stdio.dart:319:11)
#5      main (file:///tmp/a.dart:7:7)
#6      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:297:19)
#7      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)