Java linking conflict when adding Xamarin.AndroidX.Biometric in .NET MAUI 8.0 Android project

[skolesni]

Description

When including the Xamarin.AndroidX.Biometric NuGet package, a Java linking conflict occurs, causing the build to fail with a “type is defined multiple times” error for androidx.collection.ArrayMapKt. This library appears to pull conflicting references from both Xamarin.AndroidX.Collection.Jvm and Xamarin.AndroidX.Collection.Ktx in a .NET 8.0 Android environment.

Steps to Reproduce

1. Create a new .NET MAUI 8.0 Android project.
2. Add the Xamarin.AndroidX.Biometric NuGet package ().
3. Attempt to build the Android project.
4. Observe that the build fails with the Java linking conflict error.

Link to public reproduction project repository

https://github.com/skolesni/Sample.XamarinAndroidXBiometric.Issue

Version with bug

8.0.100 SR10

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

.NET MAUI 8.0 for Android (targeting Android 34)

Did you find any workaround?

Community references suggest adding Xamarin.AndroidX.Collection, Xamarin.AndroidX.Collection.Ktx, and later versions of Xamarin.AndroidX.Biometric, but these steps have not resolved the error in the affected project.

Relevant log output

Type androidx.collection.ArrayMapKt is defined multiple times:
.../xamarin.androidx.collection.jvm/...ArrayMapKt.class,
.../xamarin.androidx.collection.ktx/...ArrayMapKt.class

Error JAVA0000: Error in ...androidx.collection.collection-jvm.jar:androidx/collection/ArrayMapKt.class:
Type androidx.collection.ArrayMapKt is defined multiple times
...

java.lang.RuntimeException: com.android.tools.r8.CompilationFailedException
Caused by: com.android.tools.r8.utils.b: Type androidx.collection.ArrayMapKt is defined multiple times
...

See https://github.com/skolesni/Sample.XamarinAndroidXBiometric.Issue/blob/main/README.md for more information.

[ninachen03]

This issue has been verified using Visual Studio 17.13.0 Preview 2.1 (9.0.21). Cannot repro on android platform. but it can reproduce on 17.13.0 Preview 2.1(8.0.100 & 8.0.3)

[jfversluis]

Just tried it as well: using VS Code, with .NET 9 it all works as intended so I'm not going to spend too much time here trying to figure out why it doesn't work on .NET 8.

Please keep in mind that .NET MAUI does not have LTS releases so there should be no reason not to update to .NET 9.

[skolesni]

Dear @ninachen03 and @jfversluis, thank you for your effort verifying the issue, and finding a resolution. We will retest at our end and will confirm.

[jfversluis]

Additionally, some helpful information might be found here: dotnet/android-libraries#764