SwiftUI AttributeGraph crash on launch (rare) - swift

Question

My app in TestFlight has a few times crashed on launch, and when it decides to crash it will do so on every launch afterwards. Only way to fix it, is to reinstall the app, and then in a future time it will crash again, so I have no idea how to reproduce the crash.
I have the crash log, but I am unsure what to read from it. The app is pure SwiftUI.
Incident Identifier: 643EF787-991A-41DD-98C9-CFFCEA4C8982
CrashReporter Key: 8eb3731ae5012452a0a5758baaacba1a94696953
Hardware Model: iPhone12,3
Process: TimeMindster [5006]
Path: /private/var/containers/Bundle/Application/99C55F69-E5DA-47CF-BC59-CBC20965489F/TimeMindster.app/TimeMindster
Identifier: com.magnuskahr.TimeMindster
Version: 12 (1.0)
Code Type: ARM-64 (Native)
Role: Foreground
Parent Process: launchd [1]
Coalition: com.magnuskahr.TimeMindster [1341]
Date/Time: 2021-04-28 21:14:04.6293 +0200
Launch Time: 2021-04-28 21:14:04.0304 +0200
OS Version: iPhone OS 14.5 (18E199)
Release Type: User
Baseband Version: 2.04.07
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Application Specific Information:
abort() called
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x00000001b3a3f334 __pthread_kill + 8
1 libsystem_pthread.dylib 0x00000001d1461aa0 pthread_kill + 272
2 libsystem_c.dylib 0x000000018edc6b90 abort + 104
3 AttributeGraph 0x00000001aee71a6c util::Heap::Heap+ 121452 (void*, unsigned long, unsigned long) + 0
4 AttributeGraph 0x00000001aee5f4cc AG::Graph::any_inputs_changed+ 46284 (AG::data::ptr<AG::Node>, unsigned int const*, unsigned long) + 0
5 AttributeGraph 0x00000001aee7109c AGGraphGetValue + 232
6 SwiftUI 0x000000018c450344 MergePreferenceKeys.rhs.getter + 32
7 SwiftUI 0x000000018c450394 MergePreferenceKeys.value.getter + 52
8 SwiftUI 0x000000018c0ecf64 specialized implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 1949540 (_:) + 36
9 SwiftUI 0x000000018c148490 partial apply for specialized implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 2323600 (_:) + 48
10 AttributeGraph 0x00000001aee5977c AG::Graph::UpdateStack::update+ 22396 () + 492
11 AttributeGraph 0x00000001aee59bb4 AG::Graph::update_attribute+ 23476 (AG::data::ptr<AG::Node>, bool) + 332
12 AttributeGraph 0x00000001aee5f2fc AG::Graph::input_value_ref_slow+ 45820 (AG::data::ptr<AG::Node>, AG::AttributeID, unsigned int, AGSwiftMetadata const*, bool*, long) + 364
13 AttributeGraph 0x00000001aee7109c AGGraphGetValue + 232
14 SwiftUI 0x000000018c0bbd00 specialized HostPreferencesWriter.updateValue+ 1748224 () + 136
15 SwiftUI 0x000000018c10c5ac partial apply for specialized implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 2078124 (_:) + 24
16 AttributeGraph 0x00000001aee5977c AG::Graph::UpdateStack::update+ 22396 () + 492
17 AttributeGraph 0x00000001aee59bb4 AG::Graph::update_attribute+ 23476 (AG::data::ptr<AG::Node>, bool) + 332
18 AttributeGraph 0x00000001aee5f2fc AG::Graph::input_value_ref_slow+ 45820 (AG::data::ptr<AG::Node>, AG::AttributeID, unsigned int, AGSwiftMetadata const*, bool*, long) + 364
19 AttributeGraph 0x00000001aee7109c AGGraphGetValue + 232
20 SwiftUI 0x000000018c0bbcd8 specialized HostPreferencesWriter.updateValue+ 1748184 () + 96
21 SwiftUI 0x000000018c10c5ac partial apply for specialized implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 2078124 (_:) + 24
22 AttributeGraph 0x00000001aee5977c AG::Graph::UpdateStack::update+ 22396 () + 492
23 AttributeGraph 0x00000001aee59bb4 AG::Graph::update_attribute+ 23476 (AG::data::ptr<AG::Node>, bool) + 332
24 AttributeGraph 0x00000001aee5f2fc AG::Graph::input_value_ref_slow+ 45820 (AG::data::ptr<AG::Node>, AG::AttributeID, unsigned int, AGSwiftMetadata const*, bool*, long) + 364
25 AttributeGraph 0x00000001aee7109c AGGraphGetValue + 232
26 SwiftUI 0x000000018c0bbcd8 specialized HostPreferencesWriter.updateValue+ 1748184 () + 96
27 SwiftUI 0x000000018c10c5ac partial apply for specialized implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 2078124 (_:) + 24
28 AttributeGraph 0x00000001aee5977c AG::Graph::UpdateStack::update+ 22396 () + 492
29 AttributeGraph 0x00000001aee59bb4 AG::Graph::update_attribute+ 23476 (AG::data::ptr<AG::Node>, bool) + 332
30 AttributeGraph 0x00000001aee5f2fc AG::Graph::input_value_ref_slow+ 45820 (AG::data::ptr<AG::Node>, AG::AttributeID, unsigned int, AGSwiftMetadata const*, bool*, long) + 364
31 AttributeGraph 0x00000001aee7109c AGGraphGetValue + 232
32 SwiftUI 0x000000018c2b8ecc DynamicPreferenceCombiner.value.getter + 1028
33 SwiftUI 0x000000018c1a3144 implicit closure #2 in implicit closure #1 in closure #1 in closure #1 in Attribute.init<A>+ 2695492 (_:) + 252
34 AttributeGraph 0x00000001aee5977c AG::Graph::UpdateStack::update+ 22396 () + 492
35 AttributeGraph 0x00000001aee59bb4 AG::Graph::update_attribute+ 23476 (AG::data::ptr<AG::Node>, bool) + 332
36 AttributeGraph 0x00000001aee5ed6c AG::Graph::value_ref+ 44396 (AG::AttributeID, AGSwiftMetadata const*, bool*) + 156
37 AttributeGraph 0x00000001aee710e4 AGGraphGetValue + 304
38 SwiftUI 0x000000018c97649c GraphHost.updatePreferences+ 10900636 () + 56
39 SwiftUI 0x000000018c3fd188 ViewGraph.updateOutputs+ 5161352 (at:) + 112
40 SwiftUI 0x000000018c8c1688 closure #1 in ViewRendererHost.render+ 10159752 (interval:updateDisplayList:) + 1508
41 SwiftUI 0x000000018c8b7bdc ViewRendererHost.render+ 10120156 (interval:updateDisplayList:) + 308
42 SwiftUI 0x000000018c2cc72c closure #1 in _UIHostingView.requestImmediateUpdate+ 3913516 () + 72
43 SwiftUI 0x000000018ca4d89c thunk for #escaping #callee_guaranteed () -> + 11782300 () + 28
44 libdispatch.dylib 0x0000000185631a54 _dispatch_call_block_and_release + 32
45 libdispatch.dylib 0x00000001856337ec _dispatch_client_callout + 20
46 libdispatch.dylib 0x0000000185641c40 _dispatch_main_queue_callback_4CF + 884
47 CoreFoundation 0x00000001859c01f8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16
48 CoreFoundation 0x00000001859ba0d0 __CFRunLoopRun + 2524
49 CoreFoundation 0x00000001859b91c0 CFRunLoopRunSpecific + 600
50 GraphicsServices 0x000000019cfa1734 GSEventRunModal + 164
51 UIKitCore 0x00000001884277e4 -[UIApplication _run] + 1072
52 UIKitCore 0x000000018842d054 UIApplicationMain + 168
53 SwiftUI 0x000000018c8fd350 closure #1 in KitRendererCommon+ 10404688 (_:) + 112
54 SwiftUI 0x000000018c8fd2dc runApp<A>+ 10404572 (_:) + 224
55 SwiftUI 0x000000018c3f5b4c static App.main+ 5131084 () + 144
56 TimeMindster 0x000000010230dce0 0x102294000 + 498912
57 TimeMindster 0x000000010230dd80 0x102294000 + 499072
58 libdyld.dylib 0x0000000185675cf8 start + 4
Thread 1:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 2:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 3 name: Dispatch queue: com.apple.root.utility-qos
Thread 3:
0 libswiftCore.dylib 0x000000018994b154 swift_conformsToProtocolImpl(swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*)::$_5::operator()((anonymous namespace)::ConformanceSection const&) const::'lambda'(swift::TargetProtocolConformanceDescriptor<swift::InProcess> const&)::operator()+ 3895636 (swift::TargetProtocolConformanceDescriptor<swift::InProcess> const&) const + 40
1 libswiftCore.dylib 0x000000018994a344 swift_conformsToProtocolImpl+ 3892036 (swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*) + 596
2 libswiftCore.dylib 0x000000018994a344 swift_conformsToProtocolImpl+ 3892036 (swift::TargetMetadata<swift::InProcess> const*, swift::TargetProtocolDescriptor<swift::InProcess> const*) + 596
3 AttributeGraph 0x00000001aee65d2c AG::LayoutDescriptor::Builder::visit_element+ 73004 (AG::swift::metadata const*, AG::swift::metadata::ref_kind, unsigned long) + 212
4 AttributeGraph 0x00000001aee576d4 AG::swift::metadata_visitor::visit_field+ 14036 (AG::swift::metadata const*, AG::swift::field_record const&, unsigned long) + 96
5 AttributeGraph 0x00000001aee56e64 AG::swift::metadata::visit+ 11876 (AG::swift::metadata_visitor&) const + 820
6 AttributeGraph 0x00000001aee660e8 AG::LayoutDescriptor::Builder::visit_case+ 73960 (AG::swift::metadata const*, AG::swift::field_record const&, unsigned int) + 376
7 AttributeGraph 0x00000001aee56de0 AG::swift::metadata::visit+ 11744 (AG::swift::metadata_visitor&) const + 688
8 AttributeGraph 0x00000001aee65e08 AG::LayoutDescriptor::Builder::visit_element+ 73224 (AG::swift::metadata const*, AG::swift::metadata::ref_kind, unsigned long) + 432
9 AttributeGraph 0x00000001aee576d4 AG::swift::metadata_visitor::visit_field+ 14036 (AG::swift::metadata const*, AG::swift::field_record const&, unsigned long) + 96
10 AttributeGraph 0x00000001aee56e64 AG::swift::metadata::visit+ 11876 (AG::swift::metadata_visitor&) const + 820
11 AttributeGraph 0x00000001aee66bdc AG::LayoutDescriptor::make_layout+ 76764 (AG::swift::metadata const*, AGComparisonMode, AG::LayoutDescriptor::HeapMode) + 624
12 AttributeGraph 0x00000001aee67eb4 AG::(anonymous namespace)::LayoutCache::drain_queue+ 81588 (void*) + 152
13 libdispatch.dylib 0x00000001856337ec _dispatch_client_callout + 20
14 libdispatch.dylib 0x00000001856450dc _dispatch_root_queue_drain + 688
15 libdispatch.dylib 0x00000001856457a8 _dispatch_worker_thread2 + 112
16 libsystem_pthread.dylib 0x00000001d1462768 _pthread_wqthread + 216
17 libsystem_pthread.dylib 0x00000001d146974c start_wqthread + 8
Thread 4:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 5:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 6 name: com.apple.uikit.eventfetch-thread
Thread 6:
0 libsystem_kernel.dylib 0x00000001b3a1a4fc mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001b3a19884 mach_msg + 76
2 CoreFoundation 0x00000001859bfd10 __CFRunLoopServiceMachPort + 372
3 CoreFoundation 0x00000001859b9bb0 __CFRunLoopRun + 1212
4 CoreFoundation 0x00000001859b91c0 CFRunLoopRunSpecific + 600
5 Foundation 0x0000000186c99fac -[NSRunLoop+ 32684 (NSRunLoop) runMode:beforeDate:] + 232
6 Foundation 0x0000000186c99e78 -[NSRunLoop+ 32376 (NSRunLoop) runUntilDate:] + 92
7 UIKitCore 0x00000001884dc38c -[UIEventFetcher threadMain] + 516
8 Foundation 0x0000000186e0b2fc __NSThread__start__ + 864
9 libsystem_pthread.dylib 0x00000001d1460c00 _pthread_start + 320
10 libsystem_pthread.dylib 0x00000001d1469758 thread_start + 8
Thread 7:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 8:
0 libsystem_pthread.dylib 0x00000001d1469744 start_wqthread + 0
Thread 0 crashed with ARM Thread State (64-bit):
x0: 0x0000000000000000 x1: 0x0000000000000000 x2: 0x0000000000000000 x3: 0x0000000000000000
x4: 0x00000000000062dc x5: 0x000000000000000b x6: 0x000000000000000a x7: 0x000000000000003e
x8: 0x6f2c18735f2b4680 x9: 0x6f2c18725da73e40 x10: 0x00000000000007fd x11: 0x000000000000005e
x12: 0x0000000000000001 x13: 0x00000000d180105d x14: 0x00000000d1a01800 x15: 0x0000000000001800
x16: 0x0000000000000148 x17: 0x00000001028c78c0 x18: 0x000000011111fe1c x19: 0x0000000000000006
x20: 0x0000000000000103 x21: 0x00000001028c79a0 x22: 0x000000000001ca18 x23: 0x0000000000000000
x24: 0x0000000000000000 x25: 0x000000000000f618 x26: 0x00000001e7f20950 x27: 0x0000000102b1d66c
x28: 0x0000000102b0f418 fp: 0x000000016db69400 lr: 0x00000001d1461aa0
sp: 0x000000016db693e0 pc: 0x00000001b3a3f334 cpsr: 0x40000000
esr: 0x56000080 Address size fault

Answer 1

I had experienced same problem. It was caused by combination of AnyView and NSViewRepresentable wrapper for WKWebView. Getting rid of AnyView by rewriting helper function with #ViewBuilder fixed the problem.
Problem:
func viewFunc() -> AnyView {
switch self {
case .case1: return AnyView(ListOfWebViewWrappers())
default: return AnyView(WaitView())
}
}
Solution:
#ViewBuilder
func viewFunc() -> some View {
switch self {
case .case1: ListOfWebViewWrappers()
default: WaitView()
}
}
the #ViewBuilder allows SwiftUI to properly track each view's identity and properly manage resources. More information about view's identity: https://developer.apple.com/videos/play/wwdc2021/10022/