New Avalonia iOS app fails to build, with adjustments crashes at startup

[AArnott]

I'm trying to add iOS as the last "head" project in my solution (complementing my Windows, Linux, MacOS, Android heads), and it is crashing early in startup.
To isolate the problems, I created a whole new solution with an iOS head, With absolutely no changes made, it too fails. But it fails on build.

I notice that the project file contains this:

<RuntimeIdentifier>iossimulator-x64</RuntimeIdentifier>

Which struct me as inappropriate in my case because I have arm64 mac hardware (i.e. "Apple silicone"). So to try to fix the build break, I switched it to iossimulator-arm64, but that too fails:

1>C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk\16.4.7142\targets\Xamarin.Shared.Sdk.targets(1276,3): error : clang++ exited with code 1:
1>C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk\16.4.7142\targets\Xamarin.Shared.Sdk.targets(1276,3): error : ld: warning: ignoring duplicate libraries: '-lSystem.IO.Compression.Native', '-lSystem.Native', '-lSystem.Net.Security.Native', '-lSystem.Security.Cryptography.Native.Apple', '-lcompression', '-lmono-component-debugger', '-lmono-component-diagnostics_tracing', '-lmono-component-hot_reload', '-lmonosgen-2.0', '-lxamarin-dotnet-debug'
1>C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk\16.4.7142\targets\Xamarin.Shared.Sdk.targets(1276,3): error : ld: building for 'iOS-simulator', but linking in dylib (/Users/andrew/Library/Caches/Xamarin/mtbs/builds/AvaloniaApplication2.iOS/14bcc9c5d5ce0c7a74e7e3cf29ba554379cda8c1603996b622b8b1d39e6239ee/D:/packages/nuget/harfbuzzsharp.nativeassets.ios/2.8.2.3/runtimes/ios/native/libHarfBuzzSharp.framework/libHarfBuzzSharp) built for 'iOS'
1>C:\Program Files\dotnet\packs\Microsoft.iOS.Sdk\16.4.7142\targets\Xamarin.Shared.Sdk.targets(1276,3): error : clang: error: linker command failed with exit code 1 (use -v to see invocation)
1>Done building project "AvaloniaApplication2.iOS.csproj" -- FAILED.

So then I updated to Avalonia nuget package 11.1.0-rc2, retargeted to .NET 8, and bumped the deployment target from 10.0 to 13.0 (to address minimum targeting requirements).
That got the build working, and interestingly, it crashes in the same place as my original application near startup:

Any suggestions, please?

=================================================================
	Native Crash Reporting
=================================================================
Got a SIGBUS while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

=================================================================
	Native stacktrace:
=================================================================
	0x11bc3c250 - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_dump_native_crash_info
	0x11bbec43c - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_handle_native_crash
	0x11bb53988 - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_sigsegv_signal_handler_debug
	0x1196f37e0 - /usr/lib/system/libsystem_platform.dylib : _sigtramp
	0x1b9017ff8 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib : cvmsServerElementBuild
	0x1b9013e34 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib : cvms_element_build_from_source
	0x1b900a854 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCVMSPluginSupport.dylib : _Z26cvm_deferred_build_modularPv
	0x180171978 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_client_callout
	0x180179b10 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_lane_serial_drain
	0x18017a688 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_lane_invoke
	0x180185a84 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_root_queue_drain_deferred_wlh
	0x1801850d0 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_workloop_worker_thread
	0x11aa2f814 - /usr/lib/system/libsystem_pthread.dylib : _pthread_wqthread
	0x11aa2e5d4 - /usr/lib/system/libsystem_pthread.dylib : start_wqthread

=================================================================
	Basic Fault Address Reporting
=================================================================
Memory around native instruction pointer (0x1196f3410):0x1196f3400  28 24 40 a8 2a 2c 41 a8 21 80 00 91 42 
00 05 cb  ($@.*,A.!...B...
0x1196f3410  0c 34 00 a9 0e 3c 01 a9 42 00 01 f1 29 01 00 54  .4
...<..B...)..T
0x1196f3420  68 24 00 a9 6a 2c 01 a9 63 80 00 91 28 24 40 a8  h$..j,..c...($@.
0x1196f3430  2a 2c 41 a8 
21 80 00 91 42 80 00 f1 28 ff ff 54  *,A.!...B...(..T

=================================================================
	Native Crash Reporting
=================================================================
Got a SIGBUS while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

An error has occurred in the native fault reporting. Some diagnostic information will be unavailable.

=================================================================
	Native stacktrace:
=================================================================
	0x11bc3c250 - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_dump_native_crash_info
	0x11bbec43c - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_handle_native_crash
	0x11bb53988 - /Users/andrew/Library/Developer/CoreSimulator/Devices/74DEC6FF-CCF4-4BF8-B101-5A7E4D26C29F/data/Containers/Bundle/Application/29236BC2-79FA-4CC8-8E78-0E77CE0E4D6A/AvaloniaApplication2.iOS.app/libmonosgen-2.0.dylib : mono_sigsegv_signal_handler_debug
	0x1196f37e0 - /usr/lib/system/libsystem_platform.dylib : _sigtramp
	0x1b9017ff8 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib : cvmsServerElementBuild
	0x1b9013e34 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib : cvms_element_build_from_source
	0x1b900a854 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCVMSPluginSupport.dylib : _Z26cvm_deferred_build_modularPv
	0x180171978 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_client_callout
	0x180179b10 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_lane_serial_drain
	0x18017a688 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_lane_invoke
	0x180185a84 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_root_queue_drain_deferred_wlh
	0x1801850d0 - /Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Pro
files/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/libdispatch.dylib : _dispatch_workloop_worker_thread
	0x11aa2f814 - /usr/lib/system/libsystem_pthread.dylib : _pthread_wqthread
	0x11aa2e5d4 - /usr/lib/system/libsystem_pthread.dylib : start_wqthread

Exiting early due to double fault.

[maxkatz6]

Seems to be somewhat identical to this bug:
dotnet/macios#20657 (comment)

[AArnott]

Thanks for the tip. That talks about a workaround being to set

<ForceSimulatorX64ArchitectureInIDE>true</ForceSimulatorX64ArchitectureInIDE>

But it doesn't come with much context, including whether the simulator is actually running on x64 hardware or with an x64 image. In my case, the simulator is running on arm64 hardware, and there doesn't appear to be any option to install an x64 emulator image. But I tried adding the property anyway, and it crashed again.

I guess I'll try filing a bug of my own over there.

[maxkatz6]

You might need to switch to Metal rendering. Even though it didn't make a difference on my machine, in your case stack trace seems to come from OpenGLES.framework.

[AArnott]

How do I do that?

[maxkatz6]

See my answer on that thread dotnet/macios#20657 (comment)

[maxkatz6]

It's also enabled by default in 11.2 nightly builds. And we discuss if we should enable it for 11.1.1 too. Although it might break some apps in another yet unknown way.

[AArnott]

That solved the problem. Thank you!