Created attachment 351605 [details] get-display-media-prompt-crash-log.txt ASSERTION FAILED: !m_text.isNull() /Volumes/Data/slave/sierra-debug/build/Source/WebCore/platform/graphics/TextRun.h(60) : WebCore::TextRun::TextRun(const WTF::String &, float, float, ExpansionBehavior, WebCore::TextDirection, bool, bool) 1 0x125bd9209 WTFCrash 2 0x116ae9fdb WTFCrashWithInfo(int, char const*, char const*, int) 3 0x119022f49 WebCore::TextRun::TextRun(WTF::String const&, float, float, unsigned int, WebCore::TextDirection, bool, bool) 4 0x119011d1f WebCore::TextRun::TextRun(WTF::String const&, float, float, unsigned int, WebCore::TextDirection, bool, bool) 5 0x119a04cc3 WebCore::MockRealtimeVideoSource::drawText(WebCore::GraphicsContext&) 6 0x119a02786 WebCore::MockRealtimeVideoSource::generateFrame() 7 0x119a15405 WTF::RunLoop::Timer<WebCore::MockRealtimeVideoSource>::fired() 8 0x125c59d11 WTF::RunLoop::TimerBase::timerFired(__CFRunLoopTimer*, void*) 9 0x7fff9a3d0e04 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ 10 0x7fff9a3d0a93 __CFRunLoopDoTimer 11 0x7fff9a3d05ea __CFRunLoopDoTimers 12 0x7fff9a3c7fc1 __CFRunLoopRun 13 0x7fff9a3c7544 CFRunLoopRunSpecific 14 0x7fff99926ebc RunCurrentEventLoopInMode 15 0x7fff99926cf1 ReceiveNextEventCommon 16 0x7fff99926b26 _BlockUntilNextEventMatchingListInModeWithFilter 17 0x7fff97ebda54 _DPSNextEvent 18 0x7fff986397ee -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] 19 0x7fff97eb23db -[NSApplication run] 20 0x7fff97e7ce0e NSApplicationMain 21 0x7fffb01ea8c7 _xpc_objc_main 22 0x7fffb01e92e4 xpc_main 23 0x10f44e08e WebKit::XPCServiceMain(int, char const**) 24 0x10f44e382 main 25 0x7fffaff91235 start 26 0x1 LEAK: 1 WebPageProxy http/tests/media/media-stream/get-display-media-prompt.html is crashing consistently on macOS Sierra and HighSierra Debug and is getting an invalid crash with macOS Mojave Debug. https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2Fmedia%2Fmedia-stream%2Fget-display-media-prompt.html https://build.webkit.org/results/Apple%20Sierra%20Debug%20WK2%20(Tests)/r236828%20(8227)/results.html It looks to have started after https://trac.webkit.org/changeset/236730/webkit
<rdar://problem/45004860>
<rdar://problem/45015486>
This was rolled out in https://trac.webkit.org/changeset/236855