QAudioSink "failed to setup resampler" on start()

The following program:

int main (int argc, char *argv[]) {

    QCoreApplication a(argc, argv);

    QAudioDevice device = QMediaDevices::defaultAudioOutput();
    QAudioFormat format = device.preferredFormat();
    QAudioSink *output = new QAudioSink(device, format);
    output->start();

    return a.exec();

}

Fails to start the output device, outputting:

qt.multimedia.audiooutput: Failed to setup resampler

The equivalent code on Qt 5.15 (using QAudioDeviceInfo and QAudioOutput) works fine.

As a consequence, audio output is not possible at all in Qt6, which defeats much of the purpose of QtMultimedia.

As an aside, there's a minor typo in that error message: "set up" is two words ("setup" is a noun).