How do you get the current stacktrace in Dart for a Completer.CompleteException(exception, stackTrace);

If I understand correctly: when you catch an exception in dart, you can also catch the stack trace:

try {
  // something
} catch(e, stacktrace) {
  myCompleter.completeException(e, stacktrace);
}

If you're not in a catch block, you can use StackTrace.current