Transitive native library is embedded in consuming class library AAR and duplicated in APK

[jonathanpeppers]

Android framework version

net10.0-android

Affected platform version

.NET SDK 10.0.x with the net10.0-android workload; also reproduced with Android workload 37.0.0-preview.6.59

Description

Xamarin.AndroidX.Graphics.Path 1.1.0.1 causes its native libandroidx.graphics.path.so payload to be embedded into every consuming Android class library's generated AAR. When that class library is packed as a NuGet, the NuGet also correctly retains Xamarin.AndroidX.Graphics.Path as a dependency. An application consuming the outer NuGet therefore receives the same native library twice and reports XA4301.

The MSBuild item flow is:

1. Xamarin.AndroidX.Graphics.Path.targets adds androidx.graphics.graphics-path.aar as AndroidAarLibrary.
2. _GetLibraryImports extracts its native files as AndroidNativeLibrary.
3. For a class library, _CategorizeAndroidLibraries copies every AndroidNativeLibrary to EmbeddedNativeLibrary.
4. _CreateAar passes all EmbeddedNativeLibrary items to CreateAar, embedding them into the outer library's generated AAR.
5. NuGet packing includes that generated AAR and retains the package dependency, so an application receives both copies.

The two copies are byte-for-byte identical. This is not specific to Compose, but it is exposed by packing Microsoft.AndroidX.Compose, which depends transitively on Xamarin.AndroidX.Graphics.Path through Xamarin.AndroidX.Compose.UI.Graphics.Android.

A minimal reproduction is an Android class library with:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net10.0-android</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Xamarin.AndroidX.Graphics.Path" Version="1.1.0.1" />
  </ItemGroup>
</Project>

Run dotnet pack and inspect the resulting package:

• The generated class-library AAR contains jni/<abi>/libandroidx.graphics.path.so.
• The nuspec retains the Xamarin.AndroidX.Graphics.Path dependency.

Consume that package from a net10.0-android application and build an APK. The application sees the native library both through the outer AAR and through Xamarin.AndroidX.Graphics.Path.

Expected behavior: a native asset already supplied by a retained NuGet dependency should not also be embedded in the consuming class library's AAR. This may require package-generation changes, an Android SDK item-metadata mechanism, or limiting runtime AAR inclusion to the final application without breaking class-library Java compilation.

We are working around this in Microsoft.AndroidX.Compose by removing libandroidx.graphics.path.so from EmbeddedNativeLibrary after _CategorizeAndroidLibraries and before _CreateAarCache. The package dependency remains, and the final APK still contains one copy per selected ABI.

Relevant log output

obj/Debug/net10.0-android/lp/203/jl/jni/x86_64/libandroidx.graphics.path.so : warning XA4301: APK already contains the item lib/x86_64/libandroidx.graphics.path.so; ignoring.
obj/Debug/net10.0-android/lp/203/jl/jni/arm64-v8a/libandroidx.graphics.path.so : warning XA4301: APK already contains the item lib/arm64-v8a/libandroidx.graphics.path.so; ignoring.