This is a crash in a local build, correct? In this case, please post a local backtrace rather than a link to Socorro. You can use the Console app, or attach a debugger to obtain this. The crash report in comment 0 will not get symbolicated and is essentially useless.

Here's the relevant info from the attached crash log: Thread 29 Crashed:: Compositor 0 XUL 0x0000000111218f7c nsObserverService::NotifyObservers(nsISupports*, char const*, char16_t const*) + 556 (nsObserverService.cpp:283) 1 XUL 0x00000001137767ef mozilla::PresShell::DidPaintWindow() + 159 (nsCOMPtr.h:312) 2 XUL 0x000000011355d7f1 nsView::DidPaintWindow() + 49 (nsCOMPtr.h:313) 3 XUL 0x000000011359cc34 nsChildView::PaintWindow(mozilla::gfx::IntRegionTyped<mozilla::LayoutDevicePixel>) + 308 (nsChildView.mm:1567) 4 XUL 0x00000001135a8c16 -[ChildView drawUsingOpenGL] + 246 (nsTArray.h:371) 5 XUL 0x00000001135a85c8 -[ChildView drawRect:] + 88 (nsChildView.mm:3736) 6 com.apple.AppKit 0x00007fff2edbb405 _NSViewDrawRect + 66 7 com.apple.AppKit 0x00007fff2edc7a52 -[NSView(NSInternal) _recursive:displayRectIgnoringOpacity:inContext:shouldChangeFontReferenceColor:stopAtLayerBackedViews:] + 1545 8 com.apple.AppKit 0x00007fff2e68adfb __46-[NSView(NSLayerKitGlue) drawLayer:inContext:]_block_invoke + 192 9 com.apple.AppKit 0x00007fff2e68aa05 -[NSView(NSLayerKitGlue) _drawViewBackingLayer:inContext:drawingHandler:] + 1357 10 com.apple.AppKit 0x00007fff2e79a22e -[_NSBackingLayerContents drawLayer:inContext:] + 165 11 com.apple.QuartzCore 0x00007fff3c3e19f7 -[CALayer drawInContext:] + 281 12 com.apple.AppKit 0x00007fff2e799e88 -[_NSTiledLayer drawTile:inContext:] + 605 13 com.apple.AppKit 0x00007fff2e799bd1 -[_NSTiledLayerContents drawLayer:inContext:] + 181 14 com.apple.QuartzCore 0x00007fff3c3e19f7 -[CALayer drawInContext:] + 281 15 com.apple.AppKit 0x00007fff2e799b11 -[NSTileLayer drawInContext:] + 148 16 com.apple.QuartzCore 0x00007fff3c3e0346 CABackingStoreUpdate_ + 592 17 com.apple.QuartzCore 0x00007fff3c3e00ea invocation function for block in CA::Layer::display_() + 53 18 com.apple.QuartzCore 0x00007fff3c3df63b -[CALayer _display] + 1898 19 com.apple.AppKit 0x00007fff2e799a59 -[NSTileLayer display] + 114 20 com.apple.AppKit 0x00007fff2f09ffb3 -[_NSTiledLayerContents update:shouldCallPrepareContent:] + 4780 21 com.apple.AppKit 0x00007fff2e725bbb -[_NSTiledLayer display] + 411 22 com.apple.QuartzCore 0x00007fff3c3cf916 CA::Layer::display_if_needed(CA::Transaction*) + 634 23 com.apple.QuartzCore 0x00007fff3c3ce226 CA::Context::commit_transaction(CA::Transaction*) + 322 24 com.apple.QuartzCore 0x00007fff3c3cdbdc CA::Transaction::commit() + 576 25 com.apple.AppKit 0x00007fff2e6694b3 NSPerformVisuallyAtomicChange + 154 26 com.apple.AppKit 0x00007fff2e7dd0fa -[NSOpenGLContext setView:] + 99 27 XUL 0x00000001135a7cec -[ChildView updateGLContext] + 44 (nsChildView.mm:3646) 28 XUL 0x00000001135a714e -[ChildView preRender:] + 238 (nsChildView.mm:3420) 29 XUL 0x00000001135a0181 nsChildView::PreRender(mozilla::widget::WidgetRenderingContext*) + 113 (nsChildView.mm:2147) 30 XUL 0x0000000111e915c5 mozilla::layers::LayerManagerComposite::Render(mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&) + 645 (GeckoProfiler.h:749) 31 XUL 0x0000000111e91023 mozilla::layers::LayerManagerComposite::UpdateAndRender() + 1875 (LayerManagerComposite.cpp:538) 32 XUL 0x0000000111e90808 mozilla::layers::LayerManagerComposite::EndTransaction(mozilla::TimeStamp const&, mozilla::layers::LayerManager::EndTransactionFlags) + 200 (RefPtr.h:296) 33 XUL 0x0000000111ea880c mozilla::layers::CompositorBridgeParent::CompositeToTarget(mozilla::gfx::DrawTarget*, mozilla::gfx::IntRectTyped<mozilla::gfx::UnknownUnits> const*) + 540 (CompositorBridgeParent.cpp:1027) 34 XUL 0x0000000111ea7c52 mozilla::layers::CompositorBridgeParent::ForceComposeToTarget(mozilla::gfx::DrawTarget*, mozilla::gfx::IntRectTyped<mozilla::gfx::UnknownUnits> const*) + 178 (AutoRestore.h:45) 35 XUL 0x0000000111ea7d1d mozilla::layers::CompositorBridgeParent::RecvFlushRendering() + 125 (CompositorBridgeParent.cpp:613) 36 XUL 0x00000001119b1b57 mozilla::layers::PCompositorBridgeParent::OnMessageReceived(IPC::Message const&, IPC::Message*&) + 2567 (ProtocolUtils.h:380) 37 XUL 0x000000011172c8df mozilla::ipc::MessageChannel::DispatchSyncMessage(IPC::Message const&, IPC::Message*&) + 143 (MessageChannel.cpp:2102) 38 XUL 0x000000011172bc9f mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) + 351 (MessageChannel.cpp:2060) 39 XUL 0x000000011172c5be mozilla::ipc::MessageChannel::MessageTask::Run() + 78 (Mutex.h:70) 40 XUL 0x00000001116f8a15 MessageLoop::DoWork() + 693 (nsCOMPtr.h:354) 41 XUL 0x00000001116f9384 base::MessagePumpDefault::Run(base::MessagePump::Delegate*) + 884 (message_pump_default.cc:38) 42 XUL 0x00000001116f824b MessageLoop::Run() + 75 (message_loop.cc:598) 43 XUL 0x0000000111702199 base::Thread::ThreadMain() + 233 (thread.cc:184) 44 XUL 0x00000001116fddba ThreadFunc(void*) + 10 (platform_thread_posix.cc:39) 45 libsystem_pthread.dylib 0x00007fff5e01c7fe _pthread_body + 128 46 libsystem_pthread.dylib 0x00007fff5e01c76a _pthread_start + 70 47 libsystem_pthread.dylib 0x00007fff5e01c329 thread_start + 13

If anyone needs a work around this crash simply for testing the build out, commenting out this line does the job: https://searchfox.org/mozilla-central/rev/46292b1212d2d61d7b5a7df184406774727085b8/widget/cocoa/nsChildView.mm#1564

Marking as P3 for now. If/when we decide to build with the 10.14 SDK, this will obviously have to move up in priority.

Also got this problem while building with mojave as well. Here is the stack of the crashing thread.

Also got these messages before crash.

(In reply to Wei-Cheng Pan [:wcpan] [:wcp] [:legnaleurc] (left Mozilla) from comment #6) > Created attachment 9033336 [details] > stack.txt > > Also got this problem while building with mojave as well. > Here is the stack of the crashing thread. I have been able to reproduce this, but this no longer matches the stack in comment 0. It looks like the crash in comment 0 no longer occurs. Could you please open a new bug with the new stack?