Happens on at least macOS and Linux on current master. Also reproducible on v6.0.4, v5.0.10, and v4.2.9.
Received signal 11 SEGV_MAPERR 000000000020
0 Electron Framework 0x000000011da29da9 base::debug::CollectStackTrace(void**, unsigned long) + 9
1 Electron Framework 0x000000011d8d4b53 base::debug::StackTrace::StackTrace() + 19
2 Electron Framework 0x000000011da29c41 base::debug::(anonymous namespace)::StackDumpSignalHandler(int, __siginfo*, void*) + 2385
3 libsystem_platform.dylib 0x00007fff66ab1b5d _sigtramp + 29
4 ??? 0x00007f96d05b0f00 0x0 + 140285717450496
5 Electron Framework 0x00000001192f37bf -[AtomInspectableWebContentsView windowDidBecomeMain:] + 63
6 CoreFoundation 0x00007fff3a96137a __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
7 CoreFoundation 0x00007fff3a9612f4 ___CFXRegistrationPost_block_invoke + 63
8 CoreFoundation 0x00007fff3a96125e _CFXRegistrationPost + 404
9 CoreFoundation 0x00007fff3a96968d ___CFXNotificationPost_block_invoke + 87
10 CoreFoundation 0x00007fff3a8d276c -[_CFXNotificationRegistrar find:object:observer:enumerator:] + 1834
11 CoreFoundation 0x00007fff3a8d1a17 _CFXNotificationPost + 840
12 Foundation 0x00007fff3cb7506b -[NSNotificationCenter postNotificationName:object:userInfo:] + 66
13 AppKit 0x00007fff380c7a4a -[NSWindow _changeKeyAndMainLimitedOK:] + 972
14 AppKit 0x00007fff380c7569 -[NSWindow _makeKeyRegardlessOfVisibility] + 76
15 AppKit 0x00007fff380c7118 -[NSWindow makeKeyAndOrderFront:] + 40
16 Electron Framework 0x00000001192f3260 -[AtomInspectableWebContentsView setIsDocked:activate:] + 512
17 Electron Framework 0x00000001192f9600 electron::InspectableWebContentsImpl::SetIsDocked(base::RepeatingCallback<void (base::Value const*)> const&, bool) + 48
18 Electron Framework 0x00000001192f8ffe electron::InspectableWebContentsImpl::LoadCompleted() + 430
19 Electron Framework 0x0000000122e20c3d bool (anonymous namespace)::ParseAndHandle<>(base::RepeatingCallback<void ()> const&, base::RepeatingCallback<void (base::Value const*)> const&, base::ListValue const&) + 109
20 Electron Framework 0x0000000122e20a6a DispatcherImpl::Dispatch(base::RepeatingCallback<void (base::Value const*)> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, base::ListValue const*) + 138
21 Electron Framework 0x00000001192fabc5 electron::InspectableWebContentsImpl::HandleMessageFromDevToolsFrontend(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) + 517
22 Electron Framework 0x00000001192fc3ef base::internal::Invoker<base::internal::BindState<void (electron::InspectableWebContentsImpl::*)(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&), base::WeakPtr<electron::InspectableWebContentsImpl> >, void (std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)>::Run(base::internal::BindStateBase*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) + 191
23 Electron Framework 0x000000011ccf01e9 non-virtual thunk to content::DevToolsFrontendHostImpl::DispatchEmbedderMessage(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) + 105
24 Electron Framework 0x000000011a2934e4 blink::mojom::DevToolsFrontendHostStubDispatch::Accept(blink::mojom::DevToolsFrontendHost*, mojo::Message*) + 388
25 Electron Framework 0x000000011ddda238 mojo::InterfaceEndpointClient::HandleValidatedMessage(mojo::Message*) + 1096
26 Electron Framework 0x000000011ddd9ab6 mojo::FilterChain::Accept(mojo::Message*) + 150
27 Electron Framework 0x000000011dddb858 mojo::InterfaceEndpointClient::HandleIncomingMessage(mojo::Message*) + 120
28 Electron Framework 0x000000011e321e79 IPC::(anonymous namespace)::ChannelAssociatedGroupController::AcceptOnProxyThread(mojo::Message) + 761
29 Electron Framework 0x000000011e3221ff base::internal::Invoker<base::internal::BindState<void (IPC::(anonymous namespace)::ChannelAssociatedGroupController::*)(mojo::Message), scoped_refptr<IPC::(anonymous namespace)::ChannelAssociatedGroupController>, mojo::Message>, void ()>::RunOnce(base::internal::BindStateBase*) + 159
30 Electron Framework 0x000000011d980943 base::TaskAnnotator::RunTask(char const*, base::PendingTask*) + 355
31 Electron Framework 0x000000011d9a54ac base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::DoWorkImpl(base::sequence_manager::LazyNow*, bool*) + 652
32 Electron Framework 0x000000011d9a5c0e base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::DoDelayedWork(base::TimeTicks*) + 158
33 Electron Framework 0x000000011da5eec5 base::MessagePumpCFRunLoopBase::RunWork() + 85
34 Electron Framework 0x000000011d8c9baa base::mac::CallWithEHFrame(void () block_pointer) + 10
35 Electron Framework 0x000000011da5e68f base::MessagePumpCFRunLoopBase::RunWorkSource(void*) + 63
36 CoreFoundation 0x00007fff3a91adbb __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
37 CoreFoundation 0x00007fff3a91ad61 __CFRunLoopDoSource0 + 108
38 CoreFoundation 0x00007fff3a8fec6b __CFRunLoopDoSources0 + 195
39 CoreFoundation 0x00007fff3a8fe233 __CFRunLoopRun + 1196
40 CoreFoundation 0x00007fff3a8fdb35 CFRunLoopRunSpecific + 459
41 HIToolbox 0x00007fff39bdc96b RunCurrentEventLoopInMode + 292
42 HIToolbox 0x00007fff39bdc6a5 ReceiveNextEventCommon + 603
43 HIToolbox 0x00007fff39bdc436 _BlockUntilNextEventMatchingListInModeWithFilter + 64
44 AppKit 0x00007fff37f76987 _DPSNextEvent + 965
45 AppKit 0x00007fff37f7571f -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1361
46 AppKit 0x00007fff37f6f83c -[NSApplication run] + 699
47 Electron Framework 0x000000011da5ff4c base::MessagePumpNSApplication::DoRun(base::MessagePump::Delegate*) + 348
48 Electron Framework 0x000000011da5dff8 base::MessagePumpCFRunLoopBase::Run(base::MessagePump::Delegate*) + 136
49 Electron Framework 0x000000011d9a6232 base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::Run(bool, base::TimeDelta) + 242
50 Electron Framework 0x000000011d950a56 base::RunLoop::Run() + 726
51 Electron Framework 0x000000011c53044d content::BrowserMainLoop::RunMainMessageLoopParts() + 173
52 Electron Framework 0x000000011c532026 content::BrowserMainRunnerImpl::Run() + 102
53 Electron Framework 0x000000011c52cc7f content::BrowserMain(content::MainFunctionParams const&) + 287
54 Electron Framework 0x000000011c3602a5 content::ContentMainRunnerImpl::RunServiceManager(content::MainFunctionParams&, bool) + 949
55 Electron Framework 0x000000011c35feca content::ContentMainRunnerImpl::Run(bool) + 442
56 Electron Framework 0x000000011fdb4bb3 service_manager::Main(service_manager::MainParams const&) + 3139
57 Electron Framework 0x000000011a657ff4 content::ContentMain(content::ContentMainParams const&) + 68
58 Electron Framework 0x00000001191c3854 AtomMain + 84
59 Electron 0x000000010c55dc90 main + 240
60 libdyld.dylib 0x00007fff668c63d5 start + 1
61 ??? 0x0000000000000003 0x0 + 3
[end of stack trace]
Happens on at least macOS and Linux on current master. Also reproducible on v6.0.4, v5.0.10, and v4.2.9.
Fiddle: https://gist.github.com/6872f27344c011f3565921761b6f8f5f
Stack trace: