Grpc.Net.ClientFactory in unit test causing exception after upgrade to .Net 6.0: The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

[ncipollina]

What version of gRPC and what language are you using?

<PackageReference Include="Grpc.Net.Client" Version="2.40.0" /> <PackageReference Include="Grpc.Net.ClientFactory" Version="2.40.0" /> C#

What operating system (Linux, Windows,...) and version?

Windows 10

What runtime / compiler are you using (e.g. .NET Core SDK version dotnet --info)

.NET 6.0.100

What did you do?

We had a Unit Test project that we upgraded from .Net 5.0 to .Net 6.0 where we were unit testing a IServiceCollection extension method to inject a gRPC client to the dependency injection container. The unit test in question looks like the following:

        [Fact]
        public void AddNotificationSystemClient_NullAction_ThrowsException()
        {
            var s = new ServiceCollection();

            Action act = () => s.AddNotificationSystemClient((Action<NotificationSystemOptions>)null);

            act.Should().Throw<ArgumentNullException>();
        }

The issue is that Grpc.Net.Clientfactory 2.40.0 has a reference to Microsoft.Extensions.Http 3.0.3 which causes the following error when building.

The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

What did you expect to see?

I expected to be able to compile and run the unit test.

What did you see instead?

When building the project, I get the following build error:

The type 'ServiceCollection' exists in both 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' and 'Microsoft.Extensions.DependencyInjection, Version=3.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

Anything else we should know about your project / environment?

[chwarr]

Possible work around: try adding an explicit PackageReference to Microsoft.Extensions.DependencyInjection >= 6 to the unit test project (or the business logic project that the unit test referneces). E.g.,

<ItemGroup>
  <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.0" />
</ItemGroup>

That should cause NuGet's pick lowest behavior to see that the lowest acceptable version is no longer 3.0.3.0 but 6.0.0.

I have no idea how this project's maintainers want to resolve this long term, if at all.

[ncipollina]

This worked! Thanks @chwarr! I would be curious if there is a fix that could be implemented, but this work-around will allow me to continue for now.

[JamesNK]

This sounds like a NuGet or assembly loading problem. The lowest valid version for all apps should be chosen, which is 6.0.0 here.

There isn't anything to fix in gRPC packages.

[adityamandaleeka]

Triage: looks like there is an old reference: https://github.com/grpc/grpc-dotnet/blob/c1d3bbfccd0be49c2b711c948cad7db90bd81b65/build/dependencies.props#L15

This should be 6.0.0 or later because of the move of ServiceCollection to the Abstractions lib (https://github.com/dotnet/runtime/pull/52284).