Crash after startup after upgrade to VS 16.6.0

[rgroenewoudt]

Crash immediately after starting after upgrading Visual Studio 2019 to 16.6.0:

W/monodroid-assembly( 6433): typemap: unable to find mapping to a managed type from Java type 'androidx/fragment/app/FragmentManagerImpl'

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

No native Android stacktrace (see debuggerd output).

=================================================================
	Basic Fault Address Reporting
=================================================================
Memory around native instruction pointer (0xccd6c949):0xccd6c939  e8 c2 80 f3 ff 83 c4 10 c7 44 24 20 00 00 00 00  .........D$ ....
0xccd6c949  8b 45 00 8b 40 04 89 44 24 24 83 ec 04 6a 00 8d  .E..@..D$$...j..
0xccd6c959  44 24 18 50 56 e8 ed d0 f3 ff 89 f9 83 c4 10 85  D$.PV...........
0xccd6c969  c0 8b 54 24 40 0f 84 a1 00 00 00 89 34 24 8b 68  ..T$@.......4$.h

=============================================================

====
	Managed Stacktrace:
=================================================================
	  at <unknown> <0xffffffff>
	  at Java.Interop.TypeManager:monodroid_typemap_java_to_managed <0x00012>
	  at Java.Interop.TypeManager:GetJavaToManagedType <0x00063>
	  at Java.Interop.TypeManager:CreateInstance <0x0017f>
	  at Java.Lang.Object:GetObject <0x0014b>
	  at Java.Lang.Object:_GetObject <0x000d7>
	  at Java.Lang.Object:GetObject <0x00063>
	  at AndroidX.Core.App.ComponentActivity:get_Lifecycle <0x00107>
	  at AndroidX.Fragment.App.FragmentActivity:get_Lifecycle <0x0003f>
	  at SequriX.Android.Activities.AppActivity:Fragment.set′ <0x000f8>
	  at SequriX.Android.Activities.AppActivity:set_Fragment″ <0x0009b>
	  at ArxOne.MrAdvice.Advice.InnerMethodContext:Invoke <0x00122>
	  at ArxOne.MrAdvice.Advice.AdviceContext:InvokeNext <0x00051>
	  at ArxOne.MrAdvice.Advice.SyncAdviceContext:Proceed <0x0003f>
	  at SequriX.Shared.Helpers.Attributes.AppUiThreadAttribute:Advise <0x000ea>
	  at ArxOne.MrAdvice.Advice.Method

Version Information

VS2019 16.6.
No issues with 16.5

Project

References in my project:

Calligraphy, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Java.Interop
JetBrains.Annotations, Version=2019.1.3.0, Culture=neutral, PublicKeyToken=1010a0d8d6380325, processorArchitecture=MSIL
Microsoft.AppCenter, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.AppCenter.Analytics, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.AppCenter.Analytics.Android.Bindings, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.AppCenter.Android.Bindings, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.AppCenter.Crashes, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.AppCenter.Crashes.Android.Bindings, Version=0.0.0.0, Culture=neutral, processorArchitecture=MSIL
Microsoft.CSharp
Mono.Android
MrAdvice, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c0e7e6eab6f293d8, processorArchitecture=MSIL
Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL
NodaTime, Version=2.4.6.0, Culture=neutral, PublicKeyToken=4226afe0d9b296d1, processorArchitecture=MSIL
SQLitePCLRaw.core, Version=2.0.2.669, Culture=neutral, PublicKeyToken=1488e028ca7ab535, processorArchitecture=MSIL
SQLitePCLRaw.lib.e_sqlcipher.android, Version=2.0.2.669, Culture=neutral, PublicKeyToken=cdacefa0eb8d9dac, processorArchitecture=MSIL
SQLitePCLRaw.provider.e_sqlcipher, Version=2.0.2.669, Culture=neutral, PublicKeyToken=c242ffa62330c89b, processorArchitecture=MSIL
System
System.Buffers, Version=4.0.3.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL
System.Core
System.Data
System.Memory, Version=4.0.1.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL
System.Runtime.CompilerServices.Unsafe, Version=4.0.6.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL
System.ServiceModel
System.Xml
Xamarin.Android.Arch.Core.Common, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Arch.Lifecycle.Common, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Arch.Lifecycle.Runtime, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.Annotations, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.Collections, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.Compat, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.CustomView, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.VersionedParcelable, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.Android.Support.ViewPager, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Activity, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Annotation, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Arch.Core.Common, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Arch.Core.Runtime, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.AsyncLayoutInflater, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Collection, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.CoordinatorLayout, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Core, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.CursorAdapter, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.CustomView, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.DocumentFile, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.DrawerLayout, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Fragment, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.GridLayout, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Interpolator, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Legacy.Support.Core.UI, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Legacy.Support.Core.Utils, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Lifecycle.Common, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Lifecycle.LiveData.Core, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Lifecycle.Runtime, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Lifecycle.ViewModel, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Lifecycle.ViewModelSavedState, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Loader, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.LocalBroadcastManager, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Media, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.MultiDex, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.Print, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.SavedState, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.SlidingPaneLayout, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.SwipeRefreshLayout, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.VectorDrawable, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.VectorDrawable.Animated, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.VersionedParcelable, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.AndroidX.ViewPager, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL
Xamarin.ANRWatchDog, Version=1.4.25.0, Culture=neutral, processorArchitecture=MSIL

[grendello]

@rgroenewoudt would you be able to create a small sample app which reproduces the issue? I can't diagnose the cause from the information you provided, alas. Thanks!

[rgroenewoudt]

I'm still trying to create a sample app but I found out that I don't have any issues with <AndroidEnablePreloadAssemblies>True</AndroidEnablePreloadAssemblies>

[grendello]

@rgroenewoudt That's interesting... I will certainly need the sample to figure it out, though. Assembly preloading shouldn't have impact on the way typemaps work. What matters is whether it's a Debug or Release build and the actual contents of the type maps. That's why I need the repro.

[rgroenewoudt]

App3.zip
Sample app attached. The issue happens when AndroidEnablePreloadAssemblies is turned off in combination with AndroidX in a debug build, tested in emulator.

[rgroenewoudt]

During debugging I'm also getting messages for various classes from NuGet packages:
W/monodroid-assembly(10427): typemap: unable to find mapping to a managed type from Java type 'uk/co/chrisjenx/calligraphy/CalligraphyLayoutInflater'

[grendello]

@rgroenewoudt These messages are harmless - not all Java types are mapped. The real issue here is a segfault in Mono code, I'm investigating it now.

[grendello]

So, the crash happens because of this line in the Mono runtime. Xamarin.Android runtime uses this code to load a managed type given its name - note that it passes nullptr as the 2nd parameter, which eventually ends up passed to the Mono function mentioned earlier which crashes on the indicated line with:

05-25 14:45:29.392 11029 11029 F libc    : Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x4c0 in tid 11029 (ompanyname.app3), pid 11029 (ompanyname.app3)
05-25 14:45:29.420 11058 11058 I crash_dump64: obtaining output fd from tombstoned, type: kDebuggerdTombstone
05-25 14:45:29.420  1840  1840 I /system/bin/tombstoned: received crash request for pid 11029
05-25 14:45:29.421 11058 11058 I crash_dump64: performing dump of process 11029 (target tid = 11029)
05-25 14:45:29.427 11058 11058 F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
05-25 14:45:29.427 11058 11058 F DEBUG   : Build fingerprint: 'google/sdk_gphone_x86_64/generic_x86_64:10/QSR1.190920.001/5891938:user/release-keys'
05-25 14:45:29.427 11058 11058 F DEBUG   : Revision: '0'
05-25 14:45:29.427 11058 11058 F DEBUG   : ABI: 'x86_64'
05-25 14:45:29.427 11058 11058 F DEBUG   : Timestamp: 2020-05-25 14:45:29+0200
05-25 14:45:29.427 11058 11058 F DEBUG   : pid: 11029, tid: 11029, name: ompanyname.app3  >>> com.companyname.app3 <<<
05-25 14:45:29.427 11058 11058 F DEBUG   : uid: 10134
05-25 14:45:29.427 11058 11058 F DEBUG   : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x4c0
05-25 14:45:29.427 11058 11058 F DEBUG   : Cause: null pointer dereference
05-25 14:45:29.427 11058 11058 F DEBUG   :     rax 000000000000002f  rbx 0000000000000001  rcx 0000000000000000  rdx 0000000000000030
05-25 14:45:29.427 11058 11058 F DEBUG   :     r8  0000000000000003  r9  000000000013e2e2  r10 0173eed800000000  r11 0000000000000206
05-25 14:45:29.427 11058 11058 F DEBUG   :     r12 0000000000000000  r13 00007478530343c0  r14 00007478075eda33  r15 000074780763efb0
05-25 14:45:29.427 11058 11058 F DEBUG   :     rdi 0000000000000000  rsi 00007478e2cb14d0
05-25 14:45:29.427 11058 11058 F DEBUG   :     rbp 00007ffef3a35680  rsp 00007ffef3a355d0  rip 0000747807a4066a
05-25 14:45:29.432  1792  2471 E GnssHAL_GnssInterface: gnssSvStatusCb: a: input svInfo.flags is 8
05-25 14:45:29.432  1792  2471 E GnssHAL_GnssInterface: gnssSvStatusCb: b: input svInfo.flags is 8
05-25 14:45:29.462 11058 11058 F DEBUG   : 
05-25 14:45:29.462 11058 11058 F DEBUG   : backtrace:
05-25 14:45:29.462 11058 11058 F DEBUG   :       #00 pc 00000000003ba66a  /data/app/com.companyname.app3-aQUF6Ge6_v-WaLb5i8Q7vw==/lib/x86_64/libmonosgen-2.0.so (_mono_reflection_get_type_from_info+474)
05-25 14:45:29.462 11058 11058 F DEBUG   :       #01 pc 00000000003ba3d1  /data/app/com.companyname.app3-aQUF6Ge6_v-WaLb5i8Q7vw==/lib/x86_64/libmonosgen-2.0.so (mono_reflection_type_from_name_checked+321)
05-25 14:45:29.462 11058 11058 F DEBUG   :       #02 pc 00000000003ba26d  /data/app/com.companyname.app3-aQUF6Ge6_v-WaLb5i8Q7vw==/lib/x86_64/libmonosgen-2.0.so (mono_reflection_type_from_name+125)
05-25 14:45:29.462 11058 11058 F DEBUG   :       #03 pc 000000000000ddb5  /data/app/com.companyname.app3-aQUF6Ge6_v-WaLb5i8Q7vw==/lib/x86_64/libmonodroid.so (xamarin::android::internal::EmbeddedAssemblies::typemap_java_to_managed(char const*)+389) (BuildId: 9952f1cfe0d910ae631abc73479f88eef34fd71d)
05-25 14:45:29.462 11058 11058 F DEBUG   :       #04 pc 000000000000def3  /data/app/com.companyname.app3-aQUF6Ge6_v-WaLb5i8Q7vw==/lib/x86_64/libmonodroid.so (xamarin::android::internal::EmbeddedAssemblies::typemap_java_to_managed(_MonoString*)+99) (BuildId: 9952f1cfe0d910ae631abc73479f88eef34fd71d)
05-25 14:45:29.462 11058 11058 F DEBUG   :       #05 pc 0000000000069532  <anonymous:5ad25000>

The fix is simple and I'll be opening a PR against Mono soon. It may take a few days to propagate to Xamarin.Android/master, I'll keep this issue updated.

[grendello]

@rgroenewoudt PR for mono/master fixing this issue is up mono/mono#19839