XARRA7028 AssemblyResolutionException in Android App Release Build

[uholeschak]

Android framework version

net9.0-android

Affected platform version

VS2022 17.12.3

Description

When building and publishing an Android app in Release mode the build always fails with the following error message, but the missing System.Private.CoreLib Version=9.0.0.0 is present.
The problem is the MSBuild target _RemoveRegisterAttribute, which is run after AOT. Is seems that in this state the assembly dependencies are not accessible any more.

XARRA7028: Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: 'System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'

Steps to Reproduce

1. Create and build an Android NET9 app in release mode with the default settings:

    <AndroidPackageFormat>apk</AndroidPackageFormat>
    <AndroidLinkTool>r8</AndroidLinkTool>
    <AndroidEnableMultiDex>True</AndroidEnableMultiDex>

2. Publish the app to the target. In this step the error occurs.

Did you find any workaround?

Disable the _RemoveRegisterAttribute target by setting in Directory.Build.Props:

<Project>
  <Target Name="PatchRemoveRegisterAttributeBefore" BeforeTargets="_RemoveRegisterAttribute">
    <PropertyGroup>
      <AndroidIncludeDebugSymbolsStd>$(AndroidIncludeDebugSymbols)</AndroidIncludeDebugSymbolsStd>
      <AndroidIncludeDebugSymbols Condition=" '$(EmbedAssembliesIntoApk)' == 'True' ">True</AndroidIncludeDebugSymbols>
    </PropertyGroup>
  </Target>
  <Target Name="PatchRemoveRegisterAttributeAfter" AfterTargets="_RemoveRegisterAttribute">
    <PropertyGroup>
      <AndroidIncludeDebugSymbols Condition=" '$(EmbedAssembliesIntoApk)' == 'True' ">$(AndroidIncludeDebugSymbolsStd)</AndroidIncludeDebugSymbols>
    </PropertyGroup>
  </Target>
</Project>

Relevant log output

XARRA7028: Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: 'System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'
   bei Mono.Cecil.BaseAssemblyResolver.Resolve(AssemblyNameReference name, ReaderParameters parameters)
   bei Mono.Cecil.DefaultAssemblyResolver.Resolve(AssemblyNameReference name)
   bei Mono.Cecil.MetadataResolver.Resolve(TypeReference type)
   bei Mono.Cecil.TypeReference.Resolve()
   bei Mono.Cecil.Mixin.CheckedResolve(TypeReference self)
   bei Mono.Cecil.MetadataBuilder.GetConstantType(TypeReference constant_type, Object constant)
   bei Mono.Cecil.MetadataBuilder.AddConstant(IConstantProvider owner, TypeReference type)
   bei Mono.Cecil.MetadataBuilder.AddField(FieldDefinition field)
   bei Mono.Cecil.MetadataBuilder.AddFields(TypeDefinition type)
   bei Mono.Cecil.MetadataBuilder.AddType(TypeDefinition type)
   bei Mono.Cecil.MetadataBuilder.AddTypes()
   bei Mono.Cecil.MetadataBuilder.BuildTypes()
   bei Mono.Cecil.MetadataBuilder.BuildModule()
   bei Mono.Cecil.MetadataBuilder.BuildMetadata()
   bei Mono.Cecil.ModuleWriter.<>c.<BuildMetadata>b__2_0(MetadataBuilder builder, MetadataReader _)
   bei Mono.Cecil.ModuleDefinition.Read[TItem,TRet](TItem item, Func`3 read)
   bei Mono.Cecil.ModuleWriter.Write(ModuleDefinition module, Disposable`1 stream, WriterParameters parameters)
   bei Mono.Cecil.ModuleWriter.WriteModule(ModuleDefinition module, Disposable`1 stream, WriterParameters parameters)
   bei Mono.Cecil.ModuleDefinition.Write(Stream stream, WriterParameters parameters)
   bei Xamarin.Android.Tasks.RemoveRegisterAttribute.RunTask() in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/RemoveRegisterAttribute.cs:Zeile 33.
   bei Microsoft.Android.Build.Tasks.AndroidTask.Execute() in /Users/runner/work/1/s/xamarin-android/external/xamarin-android-tools/src/Microsoft.Android.Build.BaseTasks/AndroidTask.cs:Zeile 25.

[jonathanpeppers]

Can you attach a .binlog of the failure? https://aka.ms/binlog

You should be able to remove $(AndroidEnableMultiDex) completely as both d8 and r8 automatically do this for you.

[uholeschak]

I have created the logs when execution the publish operation in VS (when the error occurs).
The complete build logs before are not included to reduce the size.
MSBuildReproLogs.zip

[jonathanpeppers]

@uholeschak do you know how to cause this issue in a small sample?

My best guess is the code here:

android/src/Xamarin.Android.Build.Tasks/Tasks/RemoveRegisterAttribute.cs

Line 28 in ef9912a

using (var assembly = AssemblyDefinition.ReadAssembly (mono_android, new ReaderParameters { ReadWrite = true })) {

It doesn't setup SearchDirectories for Mono.Cecil, so if System.Private.CoreLib.dll needed to be loaded this is the error you would get.

But what type of code in your app would trigger this problem? We'd probably want to write a test to know it solves the problem and it doesn't return.

[uholeschak]

The problem is, that this is really a large application with many NuGet packages.
You could try to compile it yourself if you want (but the workaround above is applied, so the code is not executed during build):
https://github.com/uholeschak/ediabaslib/tree/master/BmwDeepObd
Basically I think RemoveRegisterAttribute is more or less optional. Would it be an option to simply ignore the error or convert it to a warning and continue?