Frequent crashes when changing focus

[Liquidmantis]

I've been digging through the issues and this doesn't seem related to #277 as I don't see any Skylight references. I'm able to reliably reproduce this crash after a random number of focus changes.

MacOS: 10.15.6
Yabai 3.2.1
Opacity disabled
Opacity duration 0

Sometimes there's just a delay in switching focus, other times Yabai crashes and reloads.

Process: yabai [55249]
Path: /usr/local/opt/yabai/bin/yabai
Identifier: yabai
Version: 0
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: yabai [55249]
User ID: 501

Date/Time: 2020-07-31 20:18:00.921 -0600
OS Version: Mac OS X 10.15.6 (19G73)
Report Version: 12
Bridge OS Version: 4.6 (17P6065)
Anonymous UUID: 7F2F79C1-8572-F905-70F4-C7CEBFF7B3CB

Sleep/Wake UUID: 43DEC385-F08E-4A53-98FC-CA592DADB807

Time Awake Since Boot: 23000 seconds
Time Since Wake: 18000 seconds

System Integrity Protection: disabled

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: EXC_I386_GPFLT
Exception Note: EXC_CORPSE_NOTIFY

Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [55249]

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 yabai 0x0000000109f59363 application_notification_handler + 179
1 com.apple.HIServices 0x00007fff34206f7e _XXMIGPostNotification + 717
2 com.apple.HIServices 0x00007fff3422cb13 _XPostNotification + 340
3 com.apple.HIServices 0x00007fff341e9f64 mshMIGPerform + 174
4 com.apple.CoreFoundation 0x00007fff35f37304 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION + 41
5 com.apple.CoreFoundation 0x00007fff35f37250 __CFRunLoopDoSource1 + 541
6 com.apple.CoreFoundation 0x00007fff35f35d79 __CFRunLoopRun + 2270
7 com.apple.CoreFoundation 0x00007fff35f34e3e CFRunLoopRunSpecific + 462
8 com.apple.CoreFoundation 0x00007fff35fbd489 CFRunLoopRun + 40
9 yabai 0x0000000109f669df main + 1967
10 libdyld.dylib 0x00007fff6fe08cc9 start + 1

[Liquidmantis]

I've been poking at this and found the verbose way of running Yabai.

Here is an example of successful switch between two apps:

thread: 208375808 | window_manager_create_and_add_window: Hammerspoon 47185
thread: 208375808 | window_manager_create_and_add_window: Hammerspoon 47186
thread: 208375808 | EVENT_HANDLER_DAEMON_MESSAGE: window --focus east
thread: 208375808 | EVENT_HANDLER_APPLICATION_FRONT_SWITCHED: Code - Insiders (43960)
thread: 208375808 | EVENT_HANDLER_APPLICATION_DEACTIVATED: Hyper
thread: 208375808 | EVENT_HANDLER_APPLICATION_ACTIVATED: Code - Insiders
thread: 208375808 | EVENT_HANDLER_WINDOW_FOCUSED: Code - Insiders 42279
thread: 208375808 | EVENT_HANDLER_DAEMON_MESSAGE: window --focus west
thread: 208375808 | EVENT_HANDLER_APPLICATION_FRONT_SWITCHED: Hyper (7053)
thread: 208375808 | EVENT_HANDLER_APPLICATION_DEACTIVATED: Code - Insiders
thread: 208375808 | EVENT_HANDLER_APPLICATION_ACTIVATED: Hyper
thread: 208375808 | EVENT_HANDLER_WINDOW_DESTROYED: Hammerspoon 47185
thread: 208375808 | EVENT_HANDLER_WINDOW_DESTROYED: Hammerspoon 47186

Here is an example where there was a hang:

thread: 208375808 | window_manager_create_and_add_window: Hammerspoon 47182
thread: 208375808 | window_observe_notification: kAXWindowMiniaturizedNotification failed with error kAXErrorCannotComplete
thread: 208375808 | window_observe_notification: kAXWindowDeminiaturizedNotification failed with error kAXErrorCannotComplete
thread: 208375808 | window_observe_notification: kAXUIElementDestroyedNotification failed with error kAXErrorCannotComplete
thread: 208375808 | window_manager_create_and_add_window: could not observe Hammerspoon 47183
thread: 208375808 | EVENT_HANDLER_WINDOW_DESTROYED: Hammerspoon 47180
thread: 208375808 | EVENT_HANDLER_WINDOW_DESTROYED: Hammerspoon 47181
thread: 208375808 | EVENT_HANDLER_DAEMON_MESSAGE: window --focus west
thread: 208375808 | EVENT_HANDLER_APPLICATION_FRONT_SWITCHED: Hyper (7053)
thread: 208375808 | EVENT_HANDLER_APPLICATION_DEACTIVATED: Code - Insiders
thread: 208375808 | EVENT_HANDLER_APPLICATION_ACTIVATED: Hyper
thread: 208375808 | EVENT_HANDLER_WINDOW_DESTROYED: Hammerspoon 47182

I've been trying to avoid learning and switching to skhd, but maybe that's the solution?

[Edit] Those logs led me to believe that maybe it was an issue with the hs.alert dialogs I was using for notification of Hammerspoon's mode state. I removed my hs.alerts from the mode triggers and the log lines about the Hammerspoon window creation disappeared, and I've been unable to reproduce the hang now.

[Liquidmantis]

Closing this because I haven't had any issues after disabling the Hammerspoon alerts.