[iOS / Native AOT] Bad stack trace due to unsupported marshalling behavior

[tipa]

Package

Sentry

.NET Flavor

.NET

.NET Version

8.0.2

OS

iOS

SDK Version

4.2.1

Self-Hosted Sentry Version

No response

Steps to Reproduce

Crash in NativeAOT compiled iOS app (there might be more prerequisites, like the managed exception to be marshalled to native code and back to managed).

Expected Result

Crash with useful strack trace including managed C# function from where it originated

Actual Result

Thread 0 Crashed:
0   libsystem_kernel.dylib          0x39fe95fbc         __pthread_kill
1   libsystem_pthread.dylib         0x3e519567c         pthread_kill
2   libsystem_c.dylib               0x3210abb8c         abort
3   MyXYTestApp                     0x20499ce8c         xamarin_assertion_message (runtime.m:1461)
4   MyXYTestApp                     0x20499d5d4         xamarin_process_managed_exception (runtime.m:2441)
5   MyXYTestApp                     0x20499d458         xamarin_process_managed_exception_gchandle (runtime.m:1123)
6   MyXYTestApp                     0x2049c6508         -[App application:didFinishLaunchingWithOptions:] (registrar.mm:2760)
7   UIKitCore                       0x31562361c         -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:]
8   UIKitCore                       0x315622784         -[UIApplication _callInitializationDelegatesWithActions:forCanvas:payload:fromOriginatingProcess:]
9   UIKitCore                       0x315621768         -[UIApplication _runWithMainScene:transitionContext:completion:]
10  UIKitCore                       0x3156213b4         -[_UISceneLifecycleMultiplexer completeApplicationLaunchWithFBSScene:transitionContext:]
11  UIKitCore                       0x31559dedc         _UIScenePerformActionsWithLifecycleActionMask
12  UIKitCore                       0x3156253b0         __101-[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]_block_invoke
13  UIKitCore                       0x31554ce44         -[_UISceneLifecycleMultiplexer _performBlock:withApplicationOfDeactivationReasons:fromReasons:]
14  UIKitCore                       0x31554b8bc         -[_UISceneLifecycleMultiplexer _evalTransitionToSettings:fromSettings:forceExit:withTransitionStore:]
15  UIKitCore                       0x31554b224         -[_UISceneLifecycleMultiplexer uiScene:transitionedFromState:withTransitionContext:]
16  UIKitCore                       0x31554b0f4         __186-[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]_block_invoke
17  UIKitCore                       0x31554affc         +[BSAnimationSettings(UIKit) tryAnimatingWithSettings:fromCurrentState:actions:completion:]
18  UIKitCore                       0x31554a884         _UISceneSettingsDiffActionPerformChangesWithTransitionContextAndCompletion
19  UIKitCore                       0x31554a534         -[_UIWindowSceneFBSSceneTransitionContextDrivenLifecycleSettingsDiffAction _performActionsForUIScene:withUpdatedFBSScene:settingsDiff:fromSettings:transitionContext:lifecycleActionType:]
20  UIKitCore                       0x3158ce26c         __64-[UIScene scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke.225
21  UIKitCore                       0x3155496b8         -[UIScene _emitSceneSettingsUpdateResponseForCompletion:afterSceneUpdateWork:]
22  UIKitCore                       0x315549528         -[UIScene scene:didUpdateWithDiff:transitionContext:completion:]
23  UIKitCore                       0x315661c94         -[UIApplication workspace:didCreateScene:withTransitionContext:completion:]
24  UIKitCore                       0x315661a2c         -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:]
25  FrontBoardServices              0x3419176d0         -[FBSScene _callOutQueue_didCreateWithTransitionContext:completion:]
26  FrontBoardServices              0x34191756c         __92-[FBSWorkspaceScenesClient createSceneWithIdentity:parameters:transitionContext:completion:]_block_invoke.108
27  FrontBoardServices              0x341916198         -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:]
28  FrontBoardServices              0x341921f88         __92-[FBSWorkspaceScenesClient createSceneWithIdentity:parameters:transitionContext:completion:]_block_invoke
29  libdispatch.dylib               0x320fac2fc         _dispatch_client_callout
30  libdispatch.dylib               0x320fafd44         _dispatch_block_invoke_direct
31  FrontBoardServices              0x34191251c         __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__
32  FrontBoardServices              0x34191249c         -[FBSMainRunLoopSerialQueue _targetQueue_performNextIfPossible]
33  FrontBoardServices              0x341912374         -[FBSMainRunLoopSerialQueue _performNextFromRunLoopSource]
34  CoreFoundation                  0x310fef0a8         __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
35  CoreFoundation                  0x310fee324         __CFRunLoopDoSource0
36  CoreFoundation                  0x310fecad8         __CFRunLoopDoSources0
37  CoreFoundation                  0x310feb814         __CFRunLoopRun
38  CoreFoundation                  0x310feb3f4         CFRunLoopRunSpecific
39  GraphicsServices                0x397b374f4         GSEventRunModal
40  UIKitCore                       0x31563e89c         -[UIApplication _run]
41  UIKitCore                       0x31563ded8         UIApplicationMain
42  MyXYTestApp                     0x20499034c         xamarin_UIApplicationMain (bindings.m:126)

I believe this is caused because of this event handler that changes the default marshalling behavior of exceptions: https://github.com/getsentry/sentry-dotnet/blob/bea3fcf35dc0a2787dbf9c96931ec9895989907c/src/Sentry/Platforms/Cocoa/SentrySdk.cs#L14-L17

The code was introduced after this discussion in the Xamarin repo: https://github.com/xamarin/xamarin-macios/issues/15252

According to @rolfbjarne from the .NET iOS/macOS team, CoreCLR (which is what is used on iOS when using Native AOT as well as on macOS) doesn't support MarshalManagedExceptionMode.UnwindNativeCode and therefore, this assertion is crashing the process: https://github.com/xamarin/xamarin-macios/blob/907081f787315704a01c940cf28b46b47db23df0/runtime/runtime.m#L2362-L2364 https://github.com/xamarin/xamarin-macios/blob/907081f787315704a01c940cf28b46b47db23df0/runtime/runtime.m#L2452-L2455