In order to use the Android WorkManager feature, you're told that you need to add the Nuget Package Xamarin.AndroidX.Work.Runtime. However, as soon as you do that, even if you do nothing else, your project will no longer compile. If you look at the output window, you'll likely see an error noted that looks something like this:

Caused by: com.android.tools.r8.utils.b: Type androidx.collection.ArraySetKt is defined multiple times: C:\Users\spesc.nuget\packages\xamarin.androidx.collection.jvm\1.4.5.2\buildTransitive\net8.0-android34.0....
jar\androidx.collection.collection-jvm.jar:androidx/collection/ArraySetKt.class, C:\Users\spesc.nuget
packages\xamarin.androidx.collection.ktx\1.2.0.9\buildTransitive\net6.0-android31.0....\jar\androidx.collection.collection-ktx.jar:androidx/collection/ArraySetKt.class

This can quickly become a big rat hole if you try and fix it, then it typically lists another android type error, and so on, and so on. I duplicated this on a brand new .NET MAUI project in which I had not written a single line of code nor added a single Nuget package - it was just the out of the box template.

In order to use the Android WorkManager feature, you're told that you need to add the Nuget Package Xamarin.AndroidX.Work.Runtime. However, as soon as you do that, even if you do nothing else, your project will no longer compile. If you look at the output window, you'll likely see an error noted that looks something like this:

Caused by: com.android.tools.r8.utils.b: Type androidx.collection.ArraySetKt is defined multiple times: C:\Users\spesc.nuget\packages\xamarin.androidx.collection.jvm\1.4.5.2\buildTransitive\net8.0-android34.0....
jar\androidx.collection.collection-jvm.jar:androidx/collection/ArraySetKt.class, C:\Users\spesc.nuget
packages\xamarin.androidx.collection.ktx\1.2.0.9\buildTransitive\net6.0-android31.0....\jar\androidx.collection.collection-ktx.jar:androidx/collection/ArraySetKt.class

This can quickly become a big rat hole if you try and fix it, then it typically lists another android type error, and so on, and so on. I duplicated this on a brand new .NET MAUI project in which I had not written a single line of code nor added a single Nuget package - it was just the out of the box template.

• maui

1 Answer 1

Through a lot of trial and error, I finally found a way to fix this, so I'm documenting it here. Understand that over time the versions of what needs to be updated will change, but maybe this will at least provide a template for the specific Nuget packages you need to touch.

So, with that said, here's how I got my app to compile and also use the Nuget Xamarin.AndroidX.Work.Runtime package:

1. Add this package: Xamarin.AndroidX.Work.Runtime - 2.10.0.3

2. The rest of these should be present, but you need to update them to a newer version. Below are the version upgrades I made for version 2.10.0.3 of Xamarin.AndroidX.Work.Runtime. Upgrade as follows:

• xamarin.androidx.collection.ktx - 1.4.5.2

• Xamarin.androidx.lifecycle.ViewModel - 2.8.7.2

• Xamarin.androidx.lifecycle.ViewModel.Ktx - 2.8.7.2

• Xamarin.androidx.lifecycle.ViewModelSavedState - 2.8.7.2

• Xamarin.androidx.lifecycle.Process - 2.8.7.2

• Xamarin.androidx.lifecycle.Runtime.Ktx - 2.8.7.2

After making all of these changes, I did a Clean on my project and then a Build, and it finally built again without error.