C# grandchild project DLLs not included in msbuild package

Question

I have a C# project X that references a C# project Y that references a C# project Z. So the dependency chain looks like this: X => Y => Z. There is no direct/explicit dependency X => Z. When I build a package for publication using msbuild command

msbuild DesignService.csproj /m /p:Configuration="Debug" /p:Platform="AnyCPU" /verbosity:quiet /t:Package /p:PackageLocation=X.zip /p:PackageAsSingleFile=True

I get a zip file that has DLLs for X and Y, but not Z. Then when the package is published (to an Azure App Service) I get runtime errors when a call is made to code in Z, saying the DLL can not be found. If I add Z as a direct/explicit reference in X, it works just fine. But I don't think I should have to do this.

How can I get DLLs for Z in my publish package from msbuild without adding an explicit reference in X?

Answer 1

Why does this happen

X.csproj was invoked, and because it has a project reference to Y.csproj, it invokes Y.csproj — it “goes around the back”. Z.csproj hasn’t necessarily built yet, so the build breaks.

How to fix

Follow this principle: do not use dependencies expressed in the solution file at all.

You could put a project reference in the project instead. It would look like this – note the metadata element, and all this is inside an <ItemGroup> tag of course:

<ProjectReference Include=”… foo.csproj”> 
    <ReferenceOutputAssembly>false</ReferenceOutputAssembly> 
</ProjectReference>

Although it’s tiresome to have to edit your projects in this way to make the bug go away, it’s a best practice to use project references instead and consider the solution file merely a “view”.

You’ll end up with projects that if you want can be built without a solution file.

For more details about how to fix the problem, you could refer to this blog.