As per https://ews-build.s3-us-west-2.amazonaws.com/macOS-AppleSilicon-Big-Sur-Debug-WK2-Tests-EWS/dd04162b-33043/imported/w3c/web-platform-tests/speech-api/SpeechSynthesis-speak-without-activation-fails.tentative-crash-log.txt: Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.JavaScriptCore 0x000000013f169d5c WTFCrash + 20 1 com.apple.WebCore 0x000000011927a6e0 WTFCrashWithInfo(int, char const*, char const*, int) + 32 2 com.apple.WebCore 0x000000011b1e39dc WebCore::JSEventListener::ensureJSFunction(WebCore::ScriptExecutionContext&) const + 596 3 com.apple.WebCore 0x000000011b1e2f88 WebCore::JSEventListener::handleEvent(WebCore::ScriptExecutionContext&, WebCore::Event&) + 192 4 com.apple.WebCore 0x000000011bbb7e54 WebCore::EventTarget::innerInvokeEventListeners(WebCore::Event&, WTF::Vector<WTF::RefPtr<WebCore::RegisteredEventListener, WTF::RawPtrTraits<WebCore::RegisteredEventListener>, WTF::DefaultRefDerefTraits<WebCore::RegisteredEventListener> >, 1ul, WTF::CrashOnOverflow, 2ul, WTF::FastMalloc>, WebCore::EventTarget::EventInvokePhase) + 968 5 com.apple.WebCore 0x000000011bbb7938 WebCore::EventTarget::fireEventListeners(WebCore::Event&, WebCore::EventTarget::EventInvokePhase) + 300 6 com.apple.WebCore 0x000000011bbb77f8 WebCore::EventTarget::dispatchEvent(WebCore::Event&) + 348 7 com.apple.WebCore 0x000000011ac7bb94 WebCore::SpeechSynthesis::fireEvent(WTF::AtomString const&, WebCore::SpeechSynthesisUtterance&, unsigned long, unsigned long, WTF::String const&) const + 220 8 com.apple.WebCore 0x000000011ac7c054 WebCore::SpeechSynthesis::handleSpeakingCompleted(WebCore::SpeechSynthesisUtterance&, bool) + 280 9 com.apple.WebCore 0x000000011ac7ca04 WebCore::SpeechSynthesis::didFinishSpeaking(WebCore::PlatformSpeechSynthesisUtterance&) + 80 10 com.apple.WebCore 0x000000011ac7c54c WebCore::SpeechSynthesis::didFinishSpeaking() + 88 11 com.apple.WebKit 0x0000000103d14208 WebKit::WebSpeechSynthesisClient::speak(WTF::RefPtr<WebCore::PlatformSpeechSynthesisUtterance, WTF::RawPtrTraits<WebCore::PlatformSpeechSynthesisUtterance>, WTF::DefaultRefDerefTraits<WebCore::PlatformSpeechSynthesisUtterance> >)::$_9::operator()() + 92 12 com.apple.WebKit 0x0000000103d140dc WTF::Detail::CallableWrapper<WebKit::WebSpeechSynthesisClient::speak(WTF::RefPtr<WebCore::PlatformSpeechSynthesisUtterance, WTF::RawPtrTraits<WebCore::PlatformSpeechSynthesisUtterance>, WTF::DefaultRefDerefTraits<WebCore::PlatformSpeechSynthesisUtterance> >)::$_9, void>::call() + 28 13 com.apple.WebKit 0x00000001014b5b9c WTF::Function<void ()>::operator()() const + 124 14 com.apple.WebKit 0x000000010187da38 WTF::CompletionHandler<void ()>::operator()() + 216 15 com.apple.WebKit 0x000000010422a6a8 Messages::WebPageProxy::SpeechSynthesisSetFinishedCallback::callReply(IPC::Decoder&, WTF::CompletionHandler<void ()>&&) + 28 16 com.apple.WebKit 0x0000000103d14f84 unsigned long long IPC::MessageSender::sendWithAsyncReply<Messages::WebPageProxy::SpeechSynthesisSetFinishedCallback, WTF::CompletionHandler<void ()> >(Messages::WebPageProxy::SpeechSynthesisSetFinishedCallback&&, WTF::CompletionHandler<void ()>&&, unsigned long long, WTF::OptionSet<IPC::SendOption>)::'lambda'(IPC::Decoder*)::operator()(IPC::Decoder*) + 92 17 com.apple.WebKit 0x0000000103d14e68 WTF::Detail::CallableWrapper<unsigned long long IPC::MessageSender::sendWithAsyncReply<Messages::WebPageProxy::SpeechSynthesisSetFinishedCallback, WTF::CompletionHandler<void ()> >(Messages::WebPageProxy::SpeechSynthesisSetFinishedCallback&&, WTF::CompletionHandler<void ()>&&, unsigned long long, WTF::OptionSet<IPC::SendOption>)::'lambda'(IPC::Decoder*), void, IPC::Decoder*>::call(IPC::Decoder*) + 52 18 com.apple.WebKit 0x0000000102b62248 WTF::Function<void (IPC::Decoder*)>::operator()(IPC::Decoder*) const + 156 19 com.apple.WebKit 0x0000000102b3d950 WTF::CompletionHandler<void (IPC::Decoder*)>::operator()(IPC::Decoder*) + 232 20 com.apple.WebKit 0x0000000102b3d608 IPC::Connection::dispatchMessage(IPC::Decoder&) + 292 21 com.apple.WebKit 0x0000000102b3dd7c IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 632 22 com.apple.WebKit 0x0000000102b3e3d4 IPC::Connection::dispatchOneIncomingMessage() + 216 23 com.apple.WebKit 0x0000000102b61a84 IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_15::operator()() + 72
<rdar://problem/95285802>