Known issues in .NET

.NET 8

AndroidEnableMarshalMethods=true

$(AndroidEnableMarshalMethods) is an experimental feature in .NET 8 and .NET 9 Previews.

When using it, Release builds may fail to fully launch:

• https://github.com/xamarin/xamarin-android/issues/7893
• https://github.com/xamarin/xamarin-android/issues/8253
• https://github.com/xamarin/xamarin-android/pull/7927

A workaround is to remove <AndroidEnableMarshalMethods>true</AndroidEnableMarshalMethods> in your .csproj file. Or if your application can target a single architecture: <RuntimeIdentifier>android-arm64</RuntimeIdentifier>.

We hope to address this in a future .NET 9 release.

Specifying both -f and -r to dotnet build fails to restore for multi-targeted projects

This will manifest as a build error like this:

error : The RuntimeIdentifier 'android-arm64' is invalid.

The cause is that by passing -r <runtime identifier> to 'dotnet build' that runtime identifier is used for all target frameworks in the project file when the project is restored, while it's only a valid runtime identifier for one of the target frameworks.

Potential workaround is to restore manually, and build without restoring:

$ dotnet restore
$ dotnet build --no-restore -f net6.0-android -r android-arm64

This happens with dotnet publish as well.

This will be fixed in a future version of NuGet.

Ref: https://github.com/dotnet/sdk/issues/21877.
Ref: https://github.com/NuGet/Home/issues/11653.