QTextToSpeech with flite crashes saying ©

#include <QApplication>
#include <QTextToSpeech>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);    
    auto speech = new QTextToSpeech("flite");     
    const QVector<QVoice> voices = speech->availableVoices();
    speech->setVoice(voices[0]);
    // This will not crash
    // speech->say("Hello");
    // This crashes
    speech->say("©");    
    return a.exec();
}

(gdb) bt
#0  QAudioSink::processedUSecs (this=0x0) at /usr/src/debug/qt6-multimedia/qtmultimedia/src/multimedia/audio/qaudiosink.cpp:267
#1  0x00007fffe82fe3b2 in QTextToSpeechProcessorFlite::startTokenTimer (this=0x5555558e69c0) at /usr/src/debug/qt6-speech/qtspeech/src/plugins/tts/flite/qtexttospeech_flite_processor.cpp:40
#2  0x00007fffe82ff712 in QTextToSpeechProcessorFlite::audioOutputCb (w=0x7fffc000fb50, start=<optimized out>, size=320, last=0, asi=<optimized out>) at /usr/src/debug/qt6-speech/qtspeech/src/plugins/tts/flite/qtexttospeech_flite_processor.cpp:71
#3  0x00007fffe82b5b4b in synthesis_body (params=0x7fffc000d160, str=0x7fffc0008920, fs=<optimized out>, framem=<optimized out>, cg_db=0x7fffa6f05c60 <cmu_us_slt_cg_db>, asi=0x7fffc0001450, mlsa_speed_param=<optimized out>) at ../../src/cg/cst_mlsa.c:163
#4  0x00007fffe82ac212 in cg_resynth (utt=0x7fffc0001560) at ../../src/cg/cst_cg.c:715
#5  cg_synth (utt=0x7fffc0001560) at ../../src/cg/cst_cg.c:174
#6  0x00007fffe82b5fe3 in apply_synth_method (u=<optimized out>, meth=0x7fffe82cfee0 <synth_method_text+160>) at ../../src/synth/cst_synth.c:162
#7  0x00007fffe82c2ced in flite_do_synth (u=0x7fffc0001560, voice=<optimized out>, synth=0x7fffe82b6020 <utt_synth>) at ../../src/synth/flite.c:209
#8  0x00007fffe82c2d5b in flite_synth_text (text=<optimized out>, voice=<optimized out>) at ../../src/synth/flite.c:224
#9  0x00007fffe82c3368 in flite_text_to_speech (text=<optimized out>, voice=<optimized out>, outtype=0x7fffe83071de "none") at ../../src/synth/flite.c:369
#10 0x00007fffe8300f5d in QTextToSpeechProcessorFlite::processText
    (this=0x5555558e69c0, text="©", voiceId=<optimized out>, pitch=1, rate=0, outputHandler=0x7fffe82fef70 <QTextToSpeechProcessorFlite::audioOutputCb(cst_wave_struct const*, int, int, int, cst_audio_streaming_info_struct*)>)
    at /usr/src/debug/qt6-speech/qtspeech/src/plugins/tts/flite/qtexttospeech_flite_processor.cpp:183
#11 0x00007ffff678d89f in QObject::event (this=0x5555558e69c0, e=0x5555558e24a0) at /usr/src/debug/qt6-base/qtbase/src/corelib/kernel/qobject.cpp:1452