It seems the app is killed by watchdog (after 10s limits) right after user switched the app to background. The call stack is about that iOS system is taking snapshot of the app.
It's weird the app got stuck in mach_msg_trap. Is this a system bug?
Please help us. Thousands of users meet this problem every day.
Critical Crash log is attached:
Incident Identifier: 55885EC7-08D2-449D-8DAE-79885529FDB9
Hardware Model: iPhone11,8
Path: /private/var/containers/Bundle/Application/531E98C3-646C-45A2-9F02-AC5198ACA0E0/
Version: 3.1.5 (3.1.5.45)
AppStoreTools: 13A1030d
AppVariant: 1:iPhone11,8:13
Code Type: ARM-64 (Native)
Role: Background
Parent Process: launchd [1]
Date/Time: 2021-11-11 11:21:41.5289 +0800
Launch Time: 2021-11-11 00:01:20.5495 +0800
OS Version: iPhone OS 15.0 (19A346)
Release Type: User
Baseband Version: 4.00.00
Report Version: 104
Exception Type: EXC_CRASH (SIGKILL)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Thread 0 name:
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x00000001ba71b564 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001ba71bbfc mach_msg + 76 (mach_msg.c:119)
2 QuartzCore 0x0000000187ba75dc CA::Render::Context::wait_for_synchronize(unsigned int, unsigned int*, unsigned int*, unsigned int*, int) + 104 (render-context.cpp:1255)
3 QuartzCore 0x0000000187bce61c +[CATransaction(CATransactionPrivate) synchronize] + 744 (CAContextInternal.mm:591)
4 UIKitCore 0x00000001864b55c4 -[UIApplication _performWithUICACommitStateSnapshotting:] + 96 (UIApplication.m:7606)
5 UIKitCore 0x0000000187196618 __65-[UIApplication _beginSnapshotSessionForScene:withSnapshotBlock:]_block_invoke.2690 + 348 (UIApplication.m:7873)
6 UIKitCore 0x0000000187196748 __65-[UIApplication _performSnapshotsWithAction:forScene:completion:]_block_invoke.2716 + 164 (UIApplication.m:7944)
7 FrontBoardServices 0x0000000195883aac -[FBSSceneSnapshotAction _finishAllRequests] + 72 (FBSSceneSnapshotAction.m:130)
8 FrontBoardServices 0x000000019586baac -[FBSSceneSnapshotAction _executeNextRequest] + 364 (FBSSceneSnapshotAction.m:0)
9 FrontBoardServices 0x0000000195865380 -[FBSSceneSnapshotAction executeRequestsWithHandler:completionHandler:expirationHandler:] + 316 (FBSSceneSnapshotAction.m:92)
10 UIKitCore 0x00000001864e6d6c __65-[UIApplication _performSnapshotsWithAction:forScene:completion:]_block_invoke_2 + 340 (UIApplication.m:7914)
11 UIKitCore 0x0000000186785dcc -[UIApplication _beginSnapshotSessionForScene:withSnapshotBlock:] + 1052 (UIApplication.m:7862)
12 UIKitCore 0x0000000186867ad8 __65-[UIApplication _performSnapshotsWithAction:forScene:completion:]_block_invoke + 160 (UIApplication.m:7912)
13 UIKitCore 0x00000001864e68bc -[UIScene _enableOverrideSettingsForActions:] + 68 (UIScene.m:1610)
14 UIKitCore 0x00000001868a6834 -[UIScene _performSystemSnapshotWithActions:] + 124 (UIScene.m:1635)
15 UIKitCore 0x0000000186853670 -[UIApplication _performSnapshotsWithAction:forScene:completion:] + 336 (UIApplication.m:7911)
16 UIKitCore 0x0000000186637ca4 __98-[_UISceneSnapshotBSActionsHandler _respondToActions:forFBSScene:inUIScene:fromTransitionContext:]_block_invoke_3 + 192 (_UISceneSnapshotBSActionsHandler.m:54)
17 UIKitCore 0x00000001864eea48 __98-[_UISceneSnapshotBSActionsHandler _respondToActions:forFBSScene:inUIScene:fromTransitionContext:]_block_invoke_2 + 520 (_UISceneSnapshotBSActionsHandler.m:70)
18 UIKitCore 0x0000000186424f68 -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:] + 688 (UIScene.m:1460)
19 UIKitCore 0x00000001864684f0 -[UIScene scene:didUpdateWithDiff:transitionContext:completion:] + 288 (UIScene.m:1742)
20 UIKitCore 0x00000001863f1fe0 -[UIApplicationSceneClientAgent scene:handleEvent:withCompletion:] + 492 (UIApplicationSceneClientAgent.m:80)
21 FrontBoardServices 0x000000019586d110 -[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:] + 528 (FBSScene.m:549)
22 FrontBoardServices 0x0000000195885d5c __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2 + 152 (FBSWorkspaceScenesClient.m:581)
23 FrontBoardServices 0x000000019586a6c4 -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] + 240 (FBSWorkspace.m:352)
24 FrontBoardServices 0x0000000195870b20 __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke + 396 (FBSWorkspaceScenesClient.m:580)
25 libdispatch.dylib 0x0000000183aa5950 _dispatch_client_callout + 20 (object.m:560)
26 libdispatch.dylib 0x0000000183aa93e8 _dispatch_block_invoke_direct + 264 (queue.c:489)
27 FrontBoardServices 0x000000019586bfa4 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 48 (FBSSerialQueue.m:157)
28 FrontBoardServices 0x000000019586b3e4 -[FBSSerialQueue _targetQueue_performNextIfPossible] + 220 (FBSSerialQueue.m:181)
29 FrontBoardServices 0x000000019586f9f4 -[FBSSerialQueue _performNextFromRunLoopSource] + 28 (FBSSerialQueue.m:194)
30 CoreFoundation 0x0000000183e55030 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 (CFRunLoop.c:1972)
31 CoreFoundation 0x0000000183e65cf0 __CFRunLoopDoSource0 + 208 (CFRunLoop.c:2016)
32 CoreFoundation 0x0000000183d9fff8 __CFRunLoopDoSources0 + 268 (CFRunLoop.c:2053)
33 CoreFoundation 0x0000000183da5804 __CFRunLoopRun + 820 (CFRunLoop.c:2951)
34 CoreFoundation 0x0000000183db93c8 CFRunLoopRunSpecific + 600 (CFRunLoop.c:3268)
35 GraphicsServices 0x000000019f5ca38c GSEventRunModal + 164 (GSEvent.c:2200)
36 UIKitCore 0x000000018675f0bc -[UIApplication _run] + 1100 (UIApplication.m:3457)
37 UIKitCore 0x00000001864dcbe8 UIApplicationMain + 2124 (UIApplication.m:5013)
38 XXXX 0x0000000102658840 0x10209c000 + 6015040
39 dyld 0x0000000107991a24 start + 520 (dyldMain.cpp:876)
