These tests are failing an assertion after r246714: TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextAddCustomPropertiesFromJSTest TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextAddCustomPropertiesFromObjCTest TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextSanity2 TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextSanity1 TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextBackForwardCacheTest TestWebKitAPI.WebKitLegacy.DidCreateJavaScriptContextCallJSFunctionFromObjCCallbackTest TestWebKitAPI.WebKitLegacy.ReportExceptionTest ASSERTION FAILED: m_prototype.get().isEmpty() || isValidPrototype(m_prototype.get()) /Volumes/Data/slave/mojave-debug/build/Source/JavaScriptCore/runtime/Structure.h(145) : void JSC::Structure::finishCreation(JSC::VM &) 1 0x10442fdb9 WTFCrash 2 0x104432b7b WTFCrashWithInfo(int, char const*, char const*, int) 3 0x104985dc9 JSC::Structure::finishCreation(JSC::VM&) 4 0x10496bff9 JSC::Structure::create(JSC::VM&, JSC::JSGlobalObject*, JSC::JSValue, JSC::TypeInfo const&, JSC::ClassInfo const*, unsigned char, unsigned int) 5 0x10496be85 JSC::JSCallbackObject<JSC::JSAPIWrapperObject>::createStructure(JSC::VM&, JSC::JSGlobalObject*, JSC::JSValue) 6 0x1049b6949 -[JSObjCClassInfo structureInContext:] 7 0x1049b6409 -[JSObjCClassInfo wrapperForObject:inContext:] 8 0x1049b73d1 -[JSWrapperMap jsWrapperForObject:inContext:] 9 0x10496e6bd -[JSContext(Internal) wrapperForObjCObject:] 10 0x10497a198 objectToValueWithoutCopy(JSContext*, objc_object*) 11 0x104972e4f objectToValue(JSContext*, objc_object*) 12 0x104975cc3 -[JSValue setValue:forProperty:] 13 0x104978307 -[JSValue(SubscriptSupport) setObject:forKeyedSubscript:] 14 0x10496e12c -[JSContext(SubscriptSupport) setObject:forKeyedSubscript:] 15 0x102d1ae89 -[DidCreateJavaScriptContextFrameLoadDelegate webView:didCreateJavaScriptContext:forFrame:] 16 0x10af79c39 objc_object* wtfCallIMP<objc_object*, WebView*, objc_object*, objc_object*>(void (*)(), objc_object*, objc_selector*, WebView*, objc_object*, objc_object*) 17 0x10af77ed5 CallDelegate(void (*)(), WebView*, objc_object*, objc_selector*, objc_object*, objc_object*) 18 0x10af77e75 CallFrameLoadDelegate(void (*)(), WebView*, objc_selector*, objc_object*, objc_object*) 19 0x10afb406f WebFrameLoaderClient::dispatchDidClearWindowObjectInWorld(WebCore::DOMWrapperWorld&) 20 0x1193018fc WebCore::FrameLoader::dispatchDidClearWindowObjectInWorld(WebCore::DOMWrapperWorld&) 21 0x1184431f8 WebCore::ScriptController::initScriptForWindowProxy(WebCore::JSWindowProxy&) 22 0x118497b73 WebCore::WindowProxy::createJSWindowProxyWithInitializedScript(WebCore::DOMWrapperWorld&) 23 0x118431936 WebCore::WindowProxy::jsWindowProxy(WebCore::DOMWrapperWorld&) 24 0x1184420bc WebCore::ScriptController::jsWindowProxy(WebCore::DOMWrapperWorld&) 25 0x118441ead WebCore::ScriptController::evaluateInWorld(WebCore::ScriptSourceCode const&, WebCore::DOMWrapperWorld&, WebCore::ExceptionDetails*) 26 0x11844233d WebCore::ScriptController::evaluate(WebCore::ScriptSourceCode const&, WebCore::ExceptionDetails*) 27 0x118b12af1 WebCore::ScriptElement::executeClassicScript(WebCore::ScriptSourceCode const&) 28 0x118b10f58 WebCore::ScriptElement::prepareScript(WTF::TextPosition const&, WebCore::ScriptElement::LegacyTypeSupport) 29 0x118fb1037 WebCore::HTMLScriptRunner::runScript(WebCore::ScriptElement&, WTF::TextPosition const&) 30 0x118fb0e5f WebCore::HTMLScriptRunner::execute(WTF::Ref<WebCore::ScriptElement, WTF::DumbPtrTraits<WebCore::ScriptElement> >&&, WTF::TextPosition const&) 31 0x118f97dfb WebCore::HTMLDocumentParser::runScriptsForPausedTreeBuilder() https://build.webkit.org/builders/Apple%20Mojave%20Debug%20WK2%20%28Tests%29/builds/3224/steps/run-api-tests/logs/stdio
Also seen with 34 JSC tests: https://build.webkit.org/builders/Apple%20High%20Sierra%20Debug%20JSC%20%28Tests%29/builds/3083
Yusuke, is this fixed with https://bugs.webkit.org/show_bug.cgi?id=199144?
The change was rolled out. *** This bug has been marked as a duplicate of bug 196315 ***