Starting in Xamarin.Android 10.3, "System.MemberAccessException: Cannot create an instance of ... `1[T]" in Debug configuration when using certain APIs that have both generic and non-generic versions

[brendanzagaeski]

Context: #4596
Context: #4660

For this particular test case, the issue only occurs when using the shared runtime or when the managed linker is disabled.

Partial workaround

1. Disable Use Shared Runtime under the Android Options section of the Visual Studio project property pages for the project.
2. Set the Linking setting to Sdk Assemblies Only.
3. If deploying to an emulator, click the Advanced button and add the appropriate x86 or x86_64 item under Supported architectures.

Steps to reproduce

1. Download and unzip the attached test case.
2. Ensure that a hardware device is attached and that adb is running.

3. msbuild -restore -p:Configuration=Debug -t:Install AndroidApp1\AndroidApp1.csproj
   

4. Launch the app by tapping the app icon on the target device.

Test case: ArrayAdapterApp1.zip

Expected behavior

When built and deployed with Xamarin.Android 10.2, the application launches successfully and displays Hello World! in the center of the view.

Actual behavior

When built and deployed with Xamarin.Android 10.3, the application exits during launch:

System.MemberAccessException: Cannot create an instance of Android.Widget.ArrayAdapter`1[T] because Type.ContainsGenericParameters is true.
  at System.Reflection.RuntimeConstructorInfo.DoInvoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00054] in <d772a4bbe86c4dc5b425d8ca91786b91>:0 
  at System.Reflection.RuntimeConstructorInfo.Invoke (System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <d772a4bbe86c4dc5b425d8ca91786b91>:0 
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] in <d772a4bbe86c4dc5b425d8ca91786b91>:0 
  at Java.Interop.TypeManager.CreateProxy (System.Type type, System.IntPtr handle, Android.Runtime.JniHandleOwnership transfer) [0x0001b] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at Java.Interop.TypeManager.CreateInstance (System.IntPtr handle, Android.Runtime.JniHandleOwnership transfer, System.Type targetType) [0x00111] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at Java.Lang.Object.GetObject (System.IntPtr handle, Android.Runtime.JniHandleOwnership transfer, System.Type type) [0x00023] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at Java.Lang.Object._GetObject[T] (System.IntPtr handle, Android.Runtime.JniHandleOwnership transfer) [0x00017] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at Java.Lang.Object.GetObject[T] (System.IntPtr handle, Android.Runtime.JniHandleOwnership transfer) [0x00000] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at Android.Widget.ArrayAdapter.CreateFromResource (Android.Content.Context context, System.Int32 textArrayResId, System.Int32 textViewResId) [0x0006d] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at AndroidApp1.MainActivity.OnCreate (Android.OS.Bundle savedInstanceState) [0x00031] in <51ce4ed05744482eb8a8079a399a17d2>:0 
  at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_savedInstanceState) [0x0000f] in <43cddc76fe22432dbdbcea2397b6fcd7>:0 
  at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.3(intptr,intptr,intptr)

Version information

• Xamarin.Android SDK 10.3.1.4 (d16-6/3a10de9)
  • Mono: 165f4b0
  • Java.Interop: xamarin/java.interop/d16-6@2cab35c

The issue also occurs with Visual Studio 2019 version 16.7 Preview 2:

• Xamarin.Android SDK 10.3.99.259 (d16-7/feabf52)
  • Mono: 075c3f0
  • Java.Interop: xamarin/java.interop/d16-7@d6024f1

[brendanzagaeski]

I have only been able to reproduce this in the Debug configuration (with the debug libmonodroid.so), so it seems the fixes for Release configuration builds (with the release libmonodroid.so) are still verified.

[grendello]

log-new-fastdev.txt
log-regular-fastdev.txt

I can't reproduce the issue with XA/master :( Attached you can find logcats from two cold-start (no previous version of the application on device exists, no shared runtime installed) sessions for both the "old" and the "new" (Dexes) fastdev deployment models (the former puts typemaps in libxamarin-app.so the latter in *.typemap files uploaded to the override directory). The app was tested on Pixel 3 XL running Android 10.

[brendanzagaeski]

Ah, yep. I can't reproduce either using a locally built v9.0/Mono.Android.dll from master, but a way to get the issue back is to replace the assembly with the version from CI.

Steps I followed:

1. Open the latest status on https://github.com/xamarin/xamarin-android/commits/.

2. Open the Details for the JENKINS-SIGN step.

3. Download the .vsix.

4. Extract v9.0\Mono.Android.dll:

   & "C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\Common7\IDE\Extensions\Xamarin.VisualStudio\7-Zip\7z.exe" x -r C:\Temp\Xamarin.Android.Sdk-10.4.100.108.vsix '$ReferenceAssemblies\Microsoft\Framework\MonoAndroid\v9.0\Mono.Android.dll'

5. Copy it into the local build:

   Copy-Item '$ReferenceAssemblies\Microsoft\Framework\MonoAndroid\v9.0\Mono.Android.dll' C:\Source\xamarin-android\bin\Debug\lib\xamarin.android\xbuild-frameworks\MonoAndroid\v9.0\Mono.Android.dll

6. Rebuild and redeploy the app:

   & ".\bin\Debug\bin\xabuild.exe" -restore "-t:Clean,Install" -p:Configuration=Debug -p:AndroidUseSharedRuntime=false -p:EmbedAssembliesIntoApk=true C:\Temp\ArrayAdapterApp1\AndroidApp1\AndroidApp1.csproj

   (At least one version of the issue occurs without the shared runtime, so I used that approach for this test.)

[grendello]

@brendanzagaeski It appears you don't need to get Mono.Android.dll from the vsix to reproduce. What you need is a local Release Xamarin.Android build (i.e. a make CONFIGURATION=Release one) and only the v9.0 version of the assembly causes the exception to be thrown (I tested framework versions down to v7.1, the sample app fails to build for anything older)

[brendanzagaeski]

Release status update

A new Preview version of Xamarin.Android has now been published that includes the fix for this item. The fix is not yet included in a Release version. I will update this again when a Release version is available that includes the fix.

Fix included in Xamarin.Android 11.0.0.3.

Fix included on Windows in Visual Studio 2019 version 16.7 Preview 4. To try the Preview version that includes the fix, check for the latest updates in Visual Studio Preview.

Fix included on macOS in Visual Studio 2019 for Mac version 8.7 Preview 4. To try the Preview version that includes the fix, check for the latest updates on the Preview updater channel.

[brendanzagaeski]

Release status update

A new Release version of Xamarin.Android has now been published that includes the fix for this item.

Fix included in Xamarin.Android SDK version 11.0.0.3.

Fix included on Windows in Visual Studio 2019 version 16.7. To get the new version that includes the fix, check for the latest updates or install the most recent release from https://visualstudio.microsoft.com/downloads/.

Fix included on macOS in Visual Studio 2019 for Mac version 8.7. To get the new version that includes the fix, check for the latest updates on the Stable updater channel.