Maui .NET 8 => .NET 9 linker issue

[jdlegan]

Description

I ported a Maui .NET 8 application to .NET 9 yesterday due to the impending Android API 35 edict, While the migration went ok and required little in the way of changes and iOS is building/publishing correctly, I have hit an issue with the compilation/linking which I cannot find any guidance online regarding. Issue is reproducible in both Windows and Mac build environments. Initially the error was vague and indicated an AOT issue, even with MONO_LOG_LEVEL set to debug. Either switching to a debug build or disabling AOT in a release build provides a much more concrete error, but its root causal is still unclear. Does anyone have any insight into what might be causing it?

C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\35.0.78\tools\Xamarin.Android.Common.targets(1503,3): error XAGJS7000:
      System.AggregateException: One or more errors occurred. (Object reference not set to an instance of an object.)
       ---> System.NullReferenceException: Object reference not set to an instance of an object.
         at Java.Interop.Tools.Cecil.CustomAttributeProviderRocks.GetCustomAttributes(ICustomAttributeProvider item, String attribute_fullname)+MoveNe
      xt() in /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/CustomAttributeProvid
      erRocks.cs:line 30
         at System.Linq.Enumerable.IEnumerableSelectIterator`2.MoveNext()
         at System.Linq.Enumerable.IEnumerableWhereSelectIterator`2.MoveNext()
         at Java.Interop.Tools.JavaCallableWrappers.Utilities.CecilExtensions.GetTypeRegistrationAttributes(ICustomAttributeProvider p)+MoveNext() in
      /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers
      /CecilExtensions.cs:line 159
         at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source)
         at Java.Interop.Tools.JavaCallableWrappers.Adapters.CecilImporter.CreateType(TypeDefinition type, IMetadataResolver resolver, CallableWrapper
      ReaderOptions options, String outerType) in /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.JavaCallableWrap
      pers/Java.Interop.Tools.JavaCallableWrappers.Adapters/CecilImporter.cs:line 67
         at Java.Interop.Tools.JavaCallableWrappers.Adapters.CecilImporter.CreateType(TypeDefinition type, IMetadataResolver resolver, CallableWrapper
      ReaderOptions options) in /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.
      Tools.JavaCallableWrappers.Adapters/CecilImporter.cs:line 19
         at Xamarin.Android.Tasks.JCWGenerator.CreateGenerator(TypeDefinition type, MarshalMethodsClassifier classifier, String monoInit, Boolean hasE
      xportReference, String applicationJavaClass) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Utilities/JCWGenerator.cs
      :line 183
         at Xamarin.Android.Tasks.JCWGenerator.ProcessTypes(Boolean generateCode, String androidSdkPlatform, MarshalMethodsClassifier classifier, Stri
      ng outputPath, String applicationJavaClass) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Utilities/JCWGenerator.cs:
      line 110
         at Xamarin.Android.Tasks.JCWGenerator.GenerateAndClassify(String androidSdkPlatform, String outputPath, String applicationJavaClass) in /User
      s/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Utilities/JCWGenerator.cs:line 83
         at Xamarin.Android.Tasks.GenerateJavaStubs.GenerateJavaSourcesAndMaybeClassifyMarshalMethods(AndroidTargetArch arch, Dictionary`2 assemblies,
       Dictionary`2 userAssemblies, Boolean useMarshalMethods, Boolean generateJavaCode) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android
      .Build.Tasks/Tasks/GenerateJavaStubs.cs:line 386
         at Xamarin.Android.Tasks.GenerateJavaStubs.<>c__DisplayClass146_0.<Run>b__0(KeyValuePair`2 kvp) in /Users/runner/work/1/s/xamarin-android/src
      /Xamarin.Android.Build.Tasks/Tasks/GenerateJavaStubs.cs:line 202
         at System.Threading.Tasks.Parallel.<>c__DisplayClass43_0`2.<PartitionerForEachWorker>b__1(IEnumerator& partitionState, Int64 timeout, Boolean
      & replicationDelegateYieldedBeforeCompletion)
      --- End of stack trace from previous location ---
         at System.Threading.Tasks.Parallel.<>c__DisplayClass43_0`2.<PartitionerForEachWorker>b__1(IEnumerator& partitionState, Int64 timeout, Boolean
      & replicationDelegateYieldedBeforeCompletion)
         at System.Threading.Tasks.TaskReplicator.Replica.Execute()
         --- End of inner exception stack trace ---
         at System.Threading.Tasks.TaskReplicator.Run[TState](ReplicatableUserAction`1 action, ParallelOptions options, Boolean stopOnFirstFailure)
         at System.Threading.Tasks.Parallel.PartitionerForEachWorker[TSource,TLocal](Partitioner`1 source, ParallelOptions parallelOptions, Action`1 s
      impleBody, Action`2 bodyWithState, Action`3 bodyWithStateAndIndex, Func`4 bodyWithStateAndLocal, Func`5 bodyWithEverything, Func`1 localInit, Ac
      tion`1 localFinally)
      --- End of stack trace from previous location ---
         at System.Threading.Tasks.Parallel.PartitionerForEachWorker[TSource,TLocal](Partitioner`1 source, ParallelOptions parallelOptions, Action`1 s
      impleBody, Action`2 bodyWithState, Action`3 bodyWithStateAndIndex, Func`4 bodyWithStateAndLocal, Func`5 bodyWithEverything, Func`1 localInit, Ac
      tion`1 localFinally)
         at System.Threading.Tasks.Parallel.ForEachWorker[TSource,TLocal](IEnumerable`1 source, ParallelOptions parallelOptions, Action`1 body, Action
      `2 bodyWithState, Action`3 bodyWithStateAndIndex, Func`4 bodyWithStateAndLocal, Func`5 bodyWithEverything, Func`1 localInit, Action`1 localFinal
      ly)
         at System.Threading.Tasks.Parallel.ForEach[TSource](IEnumerable`1 source, Action`1 body)
         at Xamarin.Android.Tasks.GenerateJavaStubs.Run(Boolean useMarshalMethods) in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build
      .Tasks/Tasks/GenerateJavaStubs.cs:line 194
         at Xamarin.Android.Tasks.GenerateJavaStubs.RunTask() in /Users/runner/work/1/s/xamarin-android/src/Xamarin.Android.Build.Tasks/Tasks/Generate
      JavaStubs.cs:line 102
         at 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:line 25

Reproduction Steps

Cannot reproduce the issue with a new project currently, may be configuration related but have eliminated as many differences as possible.

Expected behavior

Compilation and linking works as it did with .NET 8 and Android 34

Actual behavior

Unable to compile.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

[MichalStrehovsky]

@jonathanpeppers could you move this to dotnet/android? I don't have permissions.

[jonathanpeppers]

The bottom of the stack trace is on this line:

java-interop/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/CustomAttributeProviderRocks.cs

Line 30 in 1d4c18e

foreach (CustomAttribute custom_attribute in item.CustomAttributes) {

Moving to dotnet/java-interop.

[jonathanpeppers]

@jdlegan do you have a sample project that runs into this issue?

Could it be caused by a specific NuGet package?

[jdlegan]

@jonathanpeppers its possible and I will work towards a sample project. Earlier today I eliminated what I would call the "low hanging fruit" by taking out the Google TNP and AndroidX.Biometric packages which caused issues in the past. I am going to start removing them systematically today and am hopeful I will hit something along the way. Barring that, I will endeavor to create a sample project but my confidence that it will yield results is tenuous at best given the complexity of the current project.

[jonathanpeppers]

I could actually see it being caused by this change:

• dotnet/android@79aab5c

Does the problem go away if you build for a single RID, such as RuntimeIdentifier=android-arm64?

It doesn't look like we added any escape hatch to disable the parallelism.

[jdlegan]

@jonathanpeppers, I saw during the linking phase that there were two running in parallel yesterday so I did what you described above as a test yesterday and again just now with the same results. I attempted to do so two ways, both in the csproj as well as the CLI. I am pasting the approaches I took to verify this would yield the test results you are after. Confirming that the error message is identical even with these set (Threading.Taks.Parallel in the stack).

<PropertyGroup> <RuntimeIdentifier>android-arm64</RuntimeIdentifier> </PropertyGroup>

dotnet build MyApp.csproj -f net9.0-android -c Debug -p:TargetFrameworks=net9.0-android --runtime android-arm64

[jonathanpeppers]

Ok, so it could be a specific library causing it, if the example above is failing in the same way.

If you have a single RuntimeIdentifier, that Parallel.ForEach() call should be on a list with a single item.

[jdlegan]

@jonathanpeppers

I am going to systematically go through these throughout the day as time allows. Below is a list of ones that are still in the codebase as well as those which I have eliminated by removing and stubbing out.

Still Reviewing:

<PackageReference Include="Duende.IdentityModel" Version="7.1.0" />
<PackageReference Include="Microsoft.Extensions.Http" Version="9.0.7" />
<PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.7" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="9.0.7" />
<PackageReference Include="Microsoft.Maui.Controls.Compatibility" Version="9.0.90" />
<PackageReference Include="Microsoft.Maui.Controls" Version="9.0.90" />
<PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="8.12.1" />
<PackageReference Include="System.Text.Json" Version="9.0.7" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.Common.Java8" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.LiveData.Core.Ktx" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.LiveData" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.Process" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.Runtime.Ktx" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Lifecycle.ViewModel.Ktx" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Navigation.Common" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Navigation.Fragment" Version="2.9.1" />
<PackageReference Include="Xamarin.AndroidX.Navigation.Runtime" Version="2.9.1"  />
<PackageReference Include="Xamarin.AndroidX.Navigation.UI" Version="2.9.1" />


Eliminated:

<PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
<PackageReference Include="minver" Version="6.0.0" PrivateAssets="All" />
<PackageReference Include="Sentry.Maui" Version="5.12.0" />
<PackageReference Include="Xamarin.AndroidX.Biometric" Version="1.1.0.29" />
<PackageReference Include="Xamarin.AndroidX.Browser" Version="1.8.0.8" PrivateAssets="all" />
<PackageReference Include="Xamarin.AndroidX.Security.SecurityCrypto" Version="1.1.0.4-alpha07" PrivateAssets="all" />
<PackageReference Include="Xamarin.Google.Crypto.Tink.Android" Version="1.18.0" PrivateAssets="all" />
<PackageReference Include="ZXing.Net.Maui.Controls" Version="0.4.0" />
<PackageReference Include="ZXing.Net.Maui" Version="0.4.0" />

[jdlegan]

So it is documented, this is the output from dotnet outdated, all references, transitive or otherwise, included and up to date. Still working through them.

» Maui.Biometric
  [net9.0-android35.0]
  Microsoft.Extensions.Configuration                         9.0.7  == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7  == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7  == 9.0.7
  Microsoft.Extensions.Primitives [T]                        9.0.7  == 9.0.7
  Microsoft.Maui.Controls                                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90 == 9.0.90
  [net9.0]
  Microsoft.Extensions.Configuration                         9.0.7  == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7  == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7  == 9.0.7
  Microsoft.Extensions.Primitives [T]                        9.0.7  == 9.0.7
  Microsoft.Maui.Controls                                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90 == 9.0.90
  [net9.0-ios18.0]
  Microsoft.Extensions.Configuration                         9.0.7  == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7  == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7  == 9.0.7
  Microsoft.Extensions.Primitives [T]                        9.0.7  == 9.0.7
  Microsoft.Maui.Controls                                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90 == 9.0.90

» MyApp
  [net9.0-ios18.5]
  Microsoft.Extensions.Configuration [T]                     9.0.7  == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7  == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7  == 9.0.7
  Microsoft.Extensions.Diagnostics [T]                       9.0.7  == 9.0.7
  Microsoft.Extensions.Http                                  9.0.7  == 9.0.7
  Microsoft.Extensions.Logging [T]                           9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Abstractions [T]              9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Debug                         9.0.7  == 9.0.7
  Microsoft.Extensions.Options [T]                           9.0.7  == 9.0.7
  Microsoft.IdentityModel.JsonWebTokens [T]                  8.12.1 == 8.12.1
  Microsoft.IdentityModel.Tokens [T]                         8.12.1 == 8.12.1
  Microsoft.Maui.Controls                                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90 == 9.0.90
  System.IdentityModel.Tokens.Jwt                            8.12.1 == 8.12.1
  [net9.0]
  Microsoft.Extensions.Configuration [T]                     9.0.7  == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7  == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7  == 9.0.7
  Microsoft.Extensions.Diagnostics [T]                       9.0.7  == 9.0.7
  Microsoft.Extensions.Http                                  9.0.7  == 9.0.7
  Microsoft.Extensions.Logging [T]                           9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Abstractions [T]              9.0.7  == 9.0.7
  Microsoft.Extensions.Logging.Debug                         9.0.7  == 9.0.7
  Microsoft.Extensions.Options [T]                           9.0.7  == 9.0.7
  Microsoft.IdentityModel.JsonWebTokens [T]                  8.12.1 == 8.12.1
  Microsoft.IdentityModel.Tokens [T]                         8.12.1 == 8.12.1
  Microsoft.Maui.Controls                                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90 == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90 == 9.0.90
  System.IdentityModel.Tokens.Jwt                            8.12.1 == 8.12.1
  [net9.0-android35.0]
  Microsoft.Extensions.Configuration [T]                     9.0.7    == 9.0.7
  Microsoft.Extensions.Configuration.Abstractions [T]        9.0.7    == 9.0.7
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7    == 9.0.7
  Microsoft.Extensions.Diagnostics [T]                       9.0.7    == 9.0.7
  Microsoft.Extensions.Http                                  9.0.7    == 9.0.7
  Microsoft.Extensions.Logging [T]                           9.0.7    == 9.0.7
  Microsoft.Extensions.Logging.Abstractions [T]              9.0.7    == 9.0.7
  Microsoft.Extensions.Logging.Debug                         9.0.7    == 9.0.7
  Microsoft.Extensions.Options [T]                           9.0.7    == 9.0.7
  Microsoft.IdentityModel.JsonWebTokens [T]                  8.12.1   == 8.12.1
  Microsoft.IdentityModel.Tokens [T]                         8.12.1   == 8.12.1
  Microsoft.Maui.Controls                                    9.0.90   == 9.0.90
  Microsoft.Maui.Controls.Build.Tasks [T]                    9.0.90   == 9.0.90
  Microsoft.Maui.Controls.Compatibility                      9.0.90   == 9.0.90
  Microsoft.Maui.Controls.Core [T]                           9.0.90   == 9.0.90
  Microsoft.Maui.Controls.Xaml [T]                           9.0.90   == 9.0.90
  Microsoft.Maui.Resizetizer [T]                             9.0.90   == 9.0.90
  System.IdentityModel.Tokens.Jwt                            8.12.1   == 8.12.1
  Xamarin.AndroidX.Activity [T]                              1.10.1.2 == 1.10.1.2
  Xamarin.AndroidX.Annotation [T]                            1.9.1.4  == 1.9.1.4
  Xamarin.AndroidX.AppCompat [T]                             1.7.1    == 1.7.1
  Xamarin.AndroidX.Arch.Core.Common [T]                      2.2.0.17 == 2.2.0.17
  Xamarin.AndroidX.Arch.Core.Runtime [T]                     2.2.0.17 == 2.2.0.17
  Xamarin.AndroidX.CoordinatorLayout [T]                     1.3.0.2  == 1.3.0.2
  Xamarin.AndroidX.Core.Core.Ktx [T]                         1.16.0.2 == 1.16.0.2
  Xamarin.AndroidX.CustomView [T]                            1.2.0    == 1.2.0
  Xamarin.AndroidX.DrawerLayout [T]                          1.2.0.17 == 1.2.0.17
  Xamarin.AndroidX.Fragment.Ktx [T]                          1.8.8    == 1.8.8
  Xamarin.AndroidX.Lifecycle.Common [T]                      2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.LiveData                        2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.LiveData.Core [T]               2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.LiveData.Core.Ktx [T]           2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.LiveData.Core.Ktx               2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.Process                         2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.Runtime [T]                     2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.Runtime.Ktx                     2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.Runtime.Ktx.Android [T]         2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.ViewModel [T]                   2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.ViewModel.Ktx                   2.9.1    == 2.9.1
  Xamarin.AndroidX.Lifecycle.ViewModelSavedState [T]         2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Common                         2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Common.Android [T]             2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Fragment                       2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Runtime [T]                    2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Runtime                        2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.Runtime.Android [T]            2.9.1    == 2.9.1
  Xamarin.AndroidX.Navigation.UI                             2.9.1    == 2.9.1
  Xamarin.AndroidX.SavedState [T]                            1.3.0.1  == 1.3.0.1
  Xamarin.AndroidX.SlidingPaneLayout [T]                     1.2.0.21 == 1.2.0.21
  Xamarin.AndroidX.Startup.StartupRuntime [T]                1.2.0.4  == 1.2.0.4
  Xamarin.AndroidX.Transition [T]                            1.6.0    == 1.6.0
  Xamarin.Google.Android.Material [T]                        1.12.0.4 == 1.12.0.4
  Xamarin.JSpecify [T]                                       1.0.0.3  == 1.0.0.3
  Xamarin.Kotlin.StdLib [T]                                  2.2.0    == 2.2.0
  Xamarin.KotlinX.Coroutines.Android [T]                     1.10.2   == 1.10.2
  Xamarin.KotlinX.Coroutines.Core [T]                        1.10.2   == 1.10.2
  Xamarin.KotlinX.Serialization.Core [T]                     1.9.0    == 1.9.0

» OidcClient
  [net9.0]
  Duende.IdentityModel                                       7.1.0 == 7.1.0
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7 == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7 == 9.0.7
  System.Text.Json                                           9.0.7 == 9.0.7
  [net9.0-android35.0]
  Duende.IdentityModel                                       7.1.0 == 7.1.0
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7 == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7 == 9.0.7
  System.Text.Json                                           9.0.7 == 9.0.7
  [net9.0-ios18.0]
  Duende.IdentityModel                                       7.1.0 == 7.1.0
  Microsoft.Extensions.DependencyInjection.Abstractions [T]  9.0.7 == 9.0.7
  Microsoft.Extensions.Logging.Abstractions                  9.0.7 == 9.0.7
  System.Text.Json                                           9.0.7 == 9.0.7

[jdlegan]

@jonathanpeppers the MS template, with all other OS's stripped out and just the nuget packages reproduces the issue. I will zip it up. Do you want it attached here? I ruled out the Duende package already, leaving only the System, Xamarin and Microsoft namespaces.

[jdlegan]

It is the Xamarin.AndroidX.Navigation.* packages. Their inclusion causes the same exception in the sample project. Commenting them out allows it to build. Currently using 2.9.1, I will look at the releases and see if there is an older but compatible version that will build.

[jdlegan]

@jonathanpeppers here is a sample app. In the csproj I created two sections of references, one that works and the other that causes the issue. The difference is 2.8.9.1 vs 2.9.1. Built with:

dotnet build MauiAppAndroidReproAttempt.csproj -f net9.0-android -c Debug -p:TargetFrameworks=net9.0-android --runtime android-arm64 --disable-build-servers --no-incremental

-- EDIT: I am updating the sample. I thought all of the AndroidX libs were released with the same version. I fixed the section for the working versions to include the different versions for Navigation and Runtime. The build still works in the other same but with warnings about package. New sample will be added shortly which has everything except for the Navigation packages at 2.9.1 and the Navigation packages at 2.8.9.2 (.1 works as well).

[jdlegan]

MauiAppAndroidReproAttempt.zip