"Reference required" error when referencing NServiceBus assembly from another project

Question

We are trying to write an application that uses the NServiceBus library in a VB.NET environment. We've been stymied by errors similar to the following:

Reference required to assembly 'NServiceBus, Version=2.0.0.1071, Culture=neutral, PublicKeyToken=9fc386479f8a226c' containing the implemented interface 'NServiceBus.IMessageHandler`1'. Add one to your project.

Our project already includes references to NServiceBus.dll and NServiceBus.Core.dll from the same NServiceBus 2.0 RC2 distribution.

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Steps to reproduce:

1. Create a new VB Class Library Project (.NET 3.5)
2. Add NServiceBus.dll and NServiceBus.Core.dll as References.

3. Put the following code in Class1.vb:

   Imports NServiceBus.Sagas.Impl
   Class Test
       Public Function Foo() As SagaMessageHandler
           Return Nothing
       End Function
   End Class
   

4. You should now see the compiler error mentioned above.

An identical project written in C# has no compile errors.

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Any ideas about how to solve this problem? (And, yes, my preferred solution is switching to C#, but no, that's not an acceptable one at the moment.)

Answer 1

On a hunch that it was an ILMerge-related issue, I found this post suggesting that assembly signing might be responsible.

I downloaded the NServiceBus trunk source, opened up src/core/NServiceBus.sln, and set each of the projects in the solution to sign the assembly with NServiceBus.snk from the source tree root. The new DLLS produced after rebuilding NServiceBus fixed the compiler errors from my original post.

Answer 2

The projects are now strong named on both the trunk and the 2.0 branch.

Hope this helps!

Answer 3

I downloaded the binaries for RTM 2.0 on May 18th - I am getting the same error discussed in this thread in two separate VB.net projects. Everything is strongly named. Any thoughts?