I've been seeing a high number of BGTaskScheduler related crashes, all of them coming from iOS 18.4. I've encountered this myself once on launch upon installing my app, but haven't been able to reproduce it since, even after doing multiple relaunches and reinstalls. Crash report attached at the bottom of this post.
I am not even able to symbolicate the reports despite having the archive on my MacBook:
Does anyone know if this is an iOS 18.4 bug or am I doing something wrong when scheduling the task? Below is my code for scheduling the background task on the view that appears when my app launches:
.onChange(of: scenePhase) { newPhase in
if newPhase == .active {
#if !os(macOS)
let request = BGAppRefreshTaskRequest(identifier: "notifications")
request.earliestBeginDate = Calendar.current.date(byAdding: .hour, value: 3, to: Date())
do {
try BGTaskScheduler.shared.submit(request)
Logger.notifications.log("Background task scheduled. Earliest begin date: \(request.earliestBeginDate?.description ?? "nil", privacy: .public)")
} catch let error {
// print("Scheduling Error \(error.localizedDescription)")
Logger.notifications.error("Error scheduling background task: \(error.localizedDescription, privacy: .public)")
}
#endif
...
}
Incident Identifier: E1E01637-01CB-4F44-8C38-55B8721C0DAA Distributor ID: com.apple.TestFlight Hardware Model: iPhone14,4 Process: SubManager [678] Path: /private/var/containers/Bundle/Application/0D87594A-A61A-4E74-9ED8-EA9E238C3E1D/SubManager.app/SubManager Identifier: com.ip18.SubManager Version: 1.4.8 (321) AppStoreTools: 16C7009 AppVariant: 1:iPhone14,4:18 Beta: YES Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd [1] Coalition: com.ip18.SubManager [716] Date/Time: 2025-02-23 19:53:50.2294 +0000 Launch Time: 2025-02-23 19:53:50.0825 +0000 OS Version: iPhone OS 18.4 (22E5200s) Release Type: Beta Baseband Version: 4.51.00 Report Version: 104 Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Termination Reason: SIGNAL 6 Abort trap: 6 Terminating Process: SubManager [678] Triggered by Thread: 8 Last Exception Backtrace: 0 CoreFoundation 0x19737c364 0x197262000 + 1155940 1 libobjc.A.dylib 0x194846d0c 0x194814000 + 208140 2 Foundation 0x19668e990 0x195ef8000 + 7956880 3 BackgroundTasks 0x2301856ec -[BGTaskScheduler _unsafe_registerForTaskWithIdentifier:usingQueue:launchHandler:] + 448 (BGTaskScheduler.m:0) 4 BackgroundTasks 0x2301854ec -[BGTaskScheduler registerForTaskWithIdentifier:usingQueue:launchHandler:] + 128 (BGTaskScheduler.m:209) 5 SwiftUI 0x19be5fb4c -[BGTaskSchedulerProxy registerForTaskWithIdentifier:launchHandler:] + 220 (BackgroundTask_SPI.m:40) 6 SwiftUI 0x19c790028 closure #1 in AppRefreshBackgroundTask.register() + 344 (BackgroundTask.swift:408) 7 SwiftUI 0x19bab3e15 + 1 8 SwiftUI 0x19bc24239 + 1 9 SwiftUI 0x19ba94829 + 1 10 libswift_Concurrency.dylib 0x1a2dc3cc9 0x1a2d5f000 + 412873 Thread 0: 0 libsystem_platform.dylib 0x00000002213db284 0x2213d9000 + 8836 1 libswiftCore.dylib 0x0000000195d08bc8 0x195940000 + 3967944 2 libswiftCore.dylib 0x0000000195d11938 0x195940000 + 4004152 3 libswiftCore.dylib 0x0000000195d08ca8 0x195940000 + 3968168 4 libswiftCore.dylib 0x0000000195d18880 0x195940000 + 4032640 5 libswiftCore.dylib 0x0000000195d151c4 0x195940000 + 4018628 6 libswiftCore.dylib 0x0000000195d10b24 0x195940000 + 4000548 7 libswiftCore.dylib 0x0000000195d10718 0x195940000 + 3999512 8 libswiftCore.dylib 0x0000000195d11180 0x195940000 + 4002176 9 libswiftCore.dylib 0x0000000195d0a638 0x195940000 + 3974712 10 libswiftCore.dylib 0x0000000195cf319c 0x195940000 + 3879324 11 libswiftCore.dylib 0x0000000195cf133c 0x195940000 + 3871548 12 SwiftUICore 0x0000000256d99f64 0x256d57000 + 274276 13 libswiftCore.dylib 0x0000000195cf6cec 0x195940000 + 3894508 14 libswiftCore.dylib 0x0000000195ce3f70 0x195940000 + 3817328 15 SwiftUICore 0x0000000256d70e5c 0x256d57000 + 106076 16 SwiftUICore 0x0000000256d5f800 0x256d57000 + 34816 17 SwiftUICore 0x0000000256e432c4 0x256d57000 + 967364 18 SwiftUICore 0x0000000256e42ea8 0x256d57000 + 966312 19 SwiftUI 0x000000019bdc0690 static ViewAlias._makeViewList(view:inputs:) + 244 (ViewAlias.swift:44) 20 SwiftUI 0x000000019bdc2df4 protocol witness for static View._makeViewList(view:inputs:) in conformance TabViewStyleConfiguration<a>.Content + 88 (:0) 21 SwiftUICore 0x0000000256dde224 0x256d57000 + 553508 22 SwiftUICore 0x0000000256dc0ad4 0x256d57000 + 432852 23 SwiftUICore 0x0000000256e005b0 0x256d57000 + 693680 24 SwiftUICore 0x0000000256e03fd8 0x256d57000 + 708568 25 SwiftUICore 0x0000000256d89b54 0x256d57000 + 207700 26 SwiftUICore 0x0000000256d89780 0x256d57000 + 206720 27 SwiftUICore 0x0000000256d85f1c 0x256d57000 + 192284 28 SwiftUICore 0x0000000256d85cc8 0x256d57000 + 191688 29 SwiftUICore 0x0000000256d85c0c 0x256d57000 + 191500 30 SwiftUICore 0x0000000256dc0028 0x256d57000 + 430120 31 SwiftUICore 0x0000000256d70b0c 0x256d57000 + 105228 32 SwiftUICore 0x0000000256d86628 0x256d57000 + 194088 33 SwiftUICore 0x0000000256d88cbc 0x256d57000 + 203964 34 SwiftUICore 0x0000000256d88c38 0x256d57000 + 203832 35 SwiftUICore 0x0000000256d88b40 0x256d57000 + 203584 36 SwiftUICore 0x0000000256d71fa0 0x256d57000 + 110496 37 SwiftUICore 0x0000000256dbfe78 0x256d57000 + 429688 38 SwiftUICore 0x0000000256dc0528 0x256d57000 + 431400 39 SwiftUICore 0x0000000256dbf514 0x256d57000 + 427284 40 SwiftUICore 0x0000000256dbefd0 0x256d57000 + 425936 41 SwiftUICore 0x0000000256dbed20 0x256d57000 + 425248 42 SwiftUICore 0x0000000256dbecdc 0x256d57000 + 425180 43 SwiftUICore 0x0000000256dbe264 0x256d57000 + 422500 44 SwiftUICore 0x0000000256dbdf28 0x256d57000 + 421672 45 SwiftUICore 0x0000000256dbdb40 0x256d57000 + 420672 46 SwiftUICore 0x0000000256dbd5f0 0x256d57000 + 419312 47 SwiftUICore 0x0000000256dbce08 0x256d57000 + 417288 48 SwiftUICore 0x0000000256dbca94 0x256d57000 + 416404 49 SwiftUICore 0x0000000256d936d8 0x256d57000 + 247512 50 SwiftUICore 0x0000000256d93568 0x256d57000 + 247144 51 SwiftUICore 0x0000000256d9184c 0x256d57000 + 239692 52 SwiftUICore 0x0000000256d92344 0x256d57000 + 242500 53 SwiftUICore 0x0000000256d91c10 0x256d57000 + 240656 54 SwiftUICore 0x0000000256dd3900 0x256d57000 + 510208 55 SwiftUICore 0x0000000256dd37f4 0x256d57000 + 509940 56 SwiftUICore 0x0000000256dd375c 0x256d57000 + 509788 57 SwiftUICore 0x0000000256dd33b8 0x256d57000 + 508856 58 SwiftUICore 0x0000000256dd24e4 0x256d57000 + 505060 59 SwiftUICore 0x0000000256d7e96c 0x256d57000 + 162156 60 AttributeGraph 0x00000001c4eb1ab0 AG::Graph::UpdateStack::update() + 524 (ag-graph-update.cc:583) 61 AttributeGraph 0x00000001c4eb0674 AG::Graph::update_attribute(AG::data::ptr, unsigned int) + 420 (ag-graph-update.cc:712) 62 AttributeGraph 0x00000001c4ebe088 AG::Subgraph::update(unsigned int) + 848 (ag-subgraph.cc:759) 63 SwiftUICore 0x0000000256e90fd4 0x256d57000 + 1286100 64 SwiftUICore 0x0000000256e8fdc0 0x256d57000 + 1281472 65 SwiftUICore 0x0000000256e8f8ec 0x256d57000 + 1280236 66 SwiftUI 0x000000019bb0c264 UIHostingViewBase.layoutSubviews() + 324 (UIHostingViewBase.swift:394) 67 SwiftUI 0x000000019bb0c108 _UIHostingView.layoutSubviews() + 116 (UIHostingView.swift:701) 68 SwiftUI 0x000000019bb0c070 @objc _UIHostingView.layoutSubviews() + 36 (:0) 69 UIKitCore 0x0000000199b70360 0x199b54000 + 115552 70 QuartzCore 0x0000000198de0444 0x198dde000 + 9284 71 QuartzCore 0x0000000198ddffdc 0x198dde000 + 8156 72 QuartzCore 0x0000000198eacda0 0x198dde000 + 847264 73 QuartzCore 0x0000000198e2e914 0x198dde000 + 330004 74 UIKitCore 0x0000000199c3c41c 0x199b54000 + 951324 75 CoreFoundation 0x00000001972d6440 0x197262000 + 476224 76 CoreFoundation 0x00000001972d363c 0x197262000 + 464444 77 CoreFoundation 0x00000001972d2d3c 0x197262000 + 462140 78 CoreFoundation 0x00000001972f77f0 0x197262000 + 612336 79 GraphicsServices 0x00000001e454a190 0x1e4549000 + 4496 80 UIKitCore 0x0000000199f1e158 0x199b54000 + 3973464 81 UIKitCore 0x0000000199f1c388 0x199b54000 + 3965832 82 SwiftUI 0x000000019bb7307c closure #1 in KitRendererCommon(_:) + 168 (UIKitApp.swift:68) 83 SwiftUI 0x000000019bb72fac runApp</a><a>(_:) + 100 (UIKitApp.swift:16) 84 SwiftUI 0x000000019bb72e90 static App.main() + 180 (App.swift:136) 85 SubManager 0x0000000105086ebc 0x104fd4000 + 732860 86 dyld 0x00000001be8a3a58 start + 5964 (dyldMain.cpp:1443) Thread 1: 0 libsystem_pthread.dylib 0x00000002214859f0 start_wqthread + 0 Thread 2: 0 libsystem_kernel.dylib 0x00000001e8451e8c 0x1e844c000 + 24204 1 libsystem_malloc.dylib 0x00000001a7b107fc 0x1a7b0d000 + 14332 2 libsystem_malloc.dylib 0x00000001a7b13208 0x1a7b0d000 + 25096 3 libsqlite3.dylib 0x00000001c631e138 0x1c62bf000 + 389432 4 libsqlite3.dylib 0x00000001c6361a2c 0x1c62bf000 + 666156 5 libsqlite3.dylib 0x00000001c631b384 0x1c62bf000 + 377732 6 libsqlite3.dylib 0x00000001c63615b0 0x1c62bf000 + 665008 7 libsqlite3.dylib 0x00000001c62d40f4 0x1c62bf000 + 86260 8 libsqlite3.dylib 0x00000001c62f4f50 0x1c62bf000 + 221008 9 libsqlite3.dylib 0x00000001c62ea29c 0x1c62bf000 + 176796 10 CoreData 0x000000019f410e28 0x19f40a000 + 28200 11 CoreData 0x000000019f412e28 0x19f40a000 + 36392 12 CoreData 0x000000019f4deb40 0x19f40a000 + 871232 13 CoreData 0x000000019f6016b0 0x19f40a000 + 2062000 14 CoreData 0x000000019f6023b0 0x19f40a000 + 2065328 15 CoreData 0x000000019f6dbafc 0x19f40a000 + 2956028 16 CoreData 0x000000019f49f358 0x19f40a000 + 611160 17 CoreData 0x000000019f476830 0x19f40a000 + 444464 18 CoreData 0x000000019f43a828 0x19f40a000 + 198696 19 CoreData 0x000000019f43a5a0 0x19f40a000 + 198048 20 libdispatch.dylib 0x000000019f1e24f8 0x19f1c7000 + 111864 21 libdispatch.dylib 0x000000019f1d86d8 0x19f1c7000 + 71384 22 CoreData 0x000000019f43a488 0x19f40a000 + 197768 23 CoreData 0x000000019f43a354 0x19f40a000 + 197460 24 CoreData 0x000000019f43a224 0x19f40a000 + 197156 25 CoreData 0x000000019f439f0c 0x19f40a000 + 196364 26 CoreData 0x000000019f6dae88 0x19f40a000 + 2952840 27 CoreData 0x000000019f541c68 0x19f40a000 + 1277032 28 CoreData 0x000000019f5f0f8c 0x19f40a000 + 1994636 29 CoreData 0x000000019f6e142c 0x19f40a000 + 2978860 30 CoreData 0x000000019f5ee3b8 0x19f40a000 + 1983416 31 CoreData 0x000000019f68009c 0x19f40a000 + 2580636 32 CoreData 0x000000019f67eb04 0x19f40a000 + 2575108 33 libdispatch.dylib 0x000000019f1c8aac 0x19f1c7000 + 6828 34 libdispatch.dylib 0x000000019f1e24f8 0x19f1c7000 + 111864 35 libdispatch.dylib 0x000000019f1d12cc 0x19f1c7000 + 41676 36 libdispatch.dylib 0x000000019f1d1dc4 0x19f1c7000 + 44484 37 libdispatch.dylib 0x000000019f1dc178 0x19f1c7000 + 86392 38 libdispatch.dylib 0x000000019f1db9fc 0x19f1c7000 + 84476 39 libsystem_pthread.dylib 0x0000000221488660 _pthread_wqthread + 292 (pthread.c:2696) 40 libsystem_pthread.dylib 0x00000002214859f8 start_wqthread + 8 Thread 3: 0 libsystem_kernel.dylib 0x00000001e845191c 0x1e844c000 + 22812 1 libsystem_platform.dylib 0x00000002213dc0e0 0x2213d9000 + 12512 2 libobjc.A.dylib 0x000000019481be80 0x194814000 + 32384 3 libobjc.A.dylib 0x00000001948174e4 0x194814000 + 13540 4 Foundation 0x0000000196013310 0x195ef8000 + 1159952 5 StoreKit 0x00000001c56e64e0 0x1c55d5000 + 1119456 6 StoreKit 0x00000001c56e6b6d 0x1c55d5000 + 1121133 7 libswift_Concurrency.dylib 0x00000001a2dc3cc9 0x1a2d5f000 + 412873 Thread 4: 0 libsystem_kernel.dylib 0x00000001e844cbdc 0x1e844c000 + 3036 1 libsystem_kernel.dylib 0x00000001e8450520 0x1e844c000 + 17696 2 libxpc.dylib 0x00000002214f4d54 0x2214cf000 + 154964 3 libxpc.dylib 0x00000002214f4da0 0x2214cf000 + 155040 4 libxpc.dylib 0x00000002214f4ddc 0x2214cf000 + 155100 5 libxpc.dylib 0x00000002214df618 0x2214cf000 + 67096 6 Foundation 0x0000000195f81248 0x195ef8000 + 561736 7 Foundation 0x00000001960144c8 0x195ef8000 + 1164488 8 Foundation 0x0000000196014038 0x195ef8000 + 1163320 9 StoreKit 0x00000001c562658c 0x1c55d5000 + 333196 10 StoreKit 0x00000001c56511fc 0x1c55d5000 + 508412 11 StoreKit 0x00000001c564fa75 0x1c55d5000 + 502389 12 StoreKit 0x00000001c565b361 0x1c55d5000 + 549729 13 libswift_Concurrency.dylib 0x00000001a2dc3cc9 0x1a2d5f000 + 412873 Thread 5: 0 libsystem_pthread.dylib 0x00000002214859f0 start_wqthread + 0 Thread 6: 0 libsystem_kernel.dylib 0x00000001e844cce4 0x1e844c000 + 3300 1 libsystem_kernel.dylib 0x00000001e845039c 0x1e844c000 + 17308 2 libsystem_kernel.dylib 0x00000001e84502b8 0x1e844c000 + 17080 3 libsystem_kernel.dylib 0x00000001e8450100 0x1e844c000 + 16640 4 CoreFoundation 0x00000001972d37b0 0x197262000 + 464816 5 CoreFoundation 0x00000001972d2e90 0x197262000 + 462480 6 CoreFoundation 0x00000001972f77f0 0x197262000 + 612336 7 Foundation 0x0000000195f6c728 0x195ef8000 + 476968 8 Foundation 0x0000000195f6b558 0x195ef8000 + 472408 9 UIKitCore 0x000000019a011354 0x199b54000 + 4969300 10 Foundation 0x000000019600df40 0x195ef8000 + 1138496 11 libsystem_pthread.dylib 0x0000000221485afc _pthread_start + 136 (pthread.c:931) 12 libsystem_pthread.dylib 0x0000000221485a04 thread_start + 8 Thread 7: 0 libsystem_pthread.dylib 0x00000002214859f0 start_wqthread + 0 Thread 8 Crashed: 0 libsystem_kernel.dylib 0x00000001e84571dc 0x1e844c000 + 45532 1 libsystem_pthread.dylib 0x000000022148bb40 pthread_kill + 268 (pthread.c:1721) 2 libsystem_c.dylib 0x000000019f2841a4 abort + 124 (abort.c:122) 3 libc++abi.dylib 0x00000002213b55a0 0x22139f000 + 91552 4 libc++abi.dylib 0x00000002213a3f10 0x22139f000 + 20240 5 libobjc.A.dylib 0x0000000194848e48 0x194814000 + 216648 6 libc++abi.dylib 0x00000002213b48b4 0x22139f000 + 88244 7 libc++abi.dylib 0x00000002213b7e1c 0x22139f000 + 101916 8 libc++abi.dylib 0x00000002213b7dc4 0x22139f000 + 101828 9 libobjc.A.dylib 0x0000000194846e74 0x194814000 + 208500 10 Foundation 0x000000019668e990 0x195ef8000 + 7956880 11 BackgroundTasks 0x00000002301856ec -[BGTaskScheduler _unsafe_registerForTaskWithIdentifier:usingQueue:launchHandler:] + 448 (BGTaskScheduler.m:0) 12 BackgroundTasks 0x00000002301854ec -[BGTaskScheduler registerForTaskWithIdentifier:usingQueue:launchHandler:] + 128 (BGTaskScheduler.m:209) 13 SwiftUI 0x000000019be5fb4c -[BGTaskSchedulerProxy registerForTaskWithIdentifier:launchHandler:] + 220 (BackgroundTask_SPI.m:40) 14 SwiftUI 0x000000019c790028 closure #1 in AppRefreshBackgroundTask.register() + 344 (BackgroundTask.swift:408) 15 SwiftUI 0x000000019bab3e15 + 1 16 SwiftUI 0x000000019bc24239 + 1 17 SwiftUI 0x000000019ba94829 + 1 18 libswift_Concurrency.dylib 0x00000001a2dc3cc9 0x1a2d5f000 + 412873 Thread 9: 0 libsystem_pthread.dylib 0x00000002214859f0 start_wqthread + 0 Thread 8 crashed with ARM Thread State (64-bit): x0: 0x0000000000000000 x1: 0x0000000000000000 x2: 0x0000000000000000 x3: 0x0000000000000000 x4: 0x00000002213b9fdb x5: 0x000000016b285b70 x6: 0x000000000000006e x7: 0x38e9fa0854b0a59a x8: 0x689bd3ba61a11659 x9: 0x689bd3bb0a896659 x10: 0x0000000000000051 x11: 0x000000000000000b x12: 0x000000000000000b x13: 0x000000019771c48c x14: 0x0000000000000001 x15: 0xffffffffb00007ff x16: 0x0000000000000148 x17: 0x000000016b287000 x18: 0x0000000000000000 x19: 0x0000000000000006 x20: 0x0000000000005903 x21: 0x000000016b2870e0 x22: 0x0000000200c3c000 x23: 0x00000002052cde08 x24: 0x00000001090917c0 x25: 0x0000000000000001 x26: 0x0000000000000000 x27: 0x00000000fff0ffff x28: 0x0000000000000000 fp: 0x000000016b285ae0 lr: 0x000000022148bb40 sp: 0x000000016b285ac0 pc: 0x00000001e84571dc cpsr: 0x40001000 esr: 0x56000080 Address size fault Binary Images: 0x104fd4000 - 0x10519bfff SubManager arm64 <4aeebcac9cb03109ae8421318b46963b> /var/containers/Bundle/Application/0D87594A-A61A-4E74-9ED8-EA9E238C3E1D/SubManager.app/SubManager 0x105354000 - 0x10535ffff libobjc-trampolines.dylib arm64e /private/preboot/Cryptexes/OS/usr/lib/libobjc-trampolines.dylib 0x194814000 - 0x194865d73 libobjc.A.dylib arm64e /usr/lib/libobjc.A.dylib 0x195940000 - 0x195e9ff1f libswiftCore.dylib arm64e /usr/lib/swift/libswiftCore.dylib 0x195ef8000 - 0x196b640df Foundation arm64e <7167d9540f1939ed96a6577ecad74a5c> /System/Library/Frameworks/Foundation.framework/Foundation 0x197262000 - 0x1977ddfff CoreFoundation arm64e <992897955e433ccca76d93489fef7fdd> /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation 0x198dde000 - 0x199197e9f QuartzCore arm64e <804c69b39a57381c8b34737a7fee8895> /System/Library/Frameworks/QuartzCore.framework/QuartzCore 0x199b54000 - 0x19ba8e4df UIKitCore arm64e <89217405b3323bd6ab460d53ed8de3bf> /System/Library/PrivateFrameworks/UIKitCore.framework/UIKitCore 0x19ba8f000 - 0x19cd08f9f SwiftUI arm64e /System/Library/Frameworks/SwiftUI.framework/SwiftUI 0x19f1c7000 - 0x19f20ca3f libdispatch.dylib arm64e <2d4e905fea9d3209b037a12df57c6a09> /usr/lib/system/libdispatch.dylib 0x19f20d000 - 0x19f28c70f libsystem_c.dylib arm64e /usr/lib/system/libsystem_c.dylib 0x19f40a000 - 0x19f80165f CoreData arm64e <9c50dc8db766371486d6cc49fe6f8e2b> /System/Library/Frameworks/CoreData.framework/CoreData 0x1a2d5f000 - 0x1a2dddd4f libswift_Concurrency.dylib arm64e <8e811830512e33cd9bdb6377aade00d3> /usr/lib/swift/libswift_Concurrency.dylib 0x1a7b0d000 - 0x1a7b4cc07 libsystem_malloc.dylib arm64e <31077a87998d32f3b09ff819bfbed92b> /usr/lib/system/libsystem_malloc.dylib 0x1b3f9f000 - 0x1b472a75f CoreML arm64e <844abca32e0633d78c6bfcb0f629325e> /System/Library/Frameworks/CoreML.framework/CoreML 0x1be893000 - 0x1be92cf0f dyld arm64e <5b719cbea7093fbc8824c5d21636d2bd> /usr/lib/dyld 0x1c4ead000 - 0x1c4eefb1f AttributeGraph arm64e <8ab7a82a879938a9b3f5516c5373d92d> /System/Library/PrivateFrameworks/AttributeGraph.framework/AttributeGraph 0x1c55d5000 - 0x1c5783ddf StoreKit arm64e <91f6358d537833428d902a8f25ae80ae> /System/Library/Frameworks/StoreKit.framework/StoreKit 0x1c62bf000 - 0x1c643f73f libsqlite3.dylib arm64e <87a4a93d335937a38499ad5930d2fda9> /usr/lib/libsqlite3.dylib 0x1e4549000 - 0x1e4551c5f GraphicsServices arm64e <6b11b9c1f1003dbb89bd24f20a185c7e> /System/Library/PrivateFrameworks/GraphicsServices.framework/GraphicsServices 0x1e844c000 - 0x1e8485b87 libsystem_kernel.dylib arm64e <88a884af489138e6bd01bc71af4c7477> /usr/lib/system/libsystem_kernel.dylib 0x22139f000 - 0x2213bcfff libc++abi.dylib arm64e <2dbdca052baa3bfe9ef315a157d84058> /usr/lib/libc++abi.dylib 0x2213d9000 - 0x2213e0627 libsystem_platform.dylib arm64e <33943e1731ad350bbb229aed52a0c814> /usr/lib/system/libsystem_platform.dylib 0x221484000 - 0x2214903fb libsystem_pthread.dylib arm64e <0d89e20803853ce68691b69e35601e52> /usr/lib/system/libsystem_pthread.dylib 0x2214cf000 - 0x221516dbf libxpc.dylib arm64e <9c4b399c656a390d8afa4e7187aa58c9> /usr/lib/system/libxpc.dylib 0x230184000 - 0x23019147f BackgroundTasks arm64e <4aa4726a0519382ab80019786438277f> /System/Library/Frameworks/BackgroundTasks.framework/BackgroundTasks 0x256d57000 - 0x2578b4c3f SwiftUICore arm64e /System/Library/Frameworks/SwiftUICore.framework/SwiftUICore EOF </a>
Submitted a bug report: FB16595418
Looking the data over, I think this is bug on our side, as the crash is actually coming from SwiftUI's background task integration, not your own code. It's possible there is a timing issue between your usage and SwiftUI, but that would still mean that SwiftUI changed "something" that altered the timing of activity.
When do you call "BGTaskScheduler.register(forTaskWithIdentifier:using:launchHandler:)"? That's the one behavior you have control over which could be a factor in this crash.
Having said all that, please replicate the issue a few time, collect a sysdiagnose, upload it to your bug, and then let me know here when all of that is done. The sysdiagnose should clarify exactly what's going wrong.
__
Kevin Elliott
DTS Engineer, CoreOS/Hardware