All projects referencing sub-project must install NuGet package Microsoft.Bcl.Build (C#/Windows Phone 7)?

Question

I'm having a particularly difficult refactoring session involving a C# solution with multiple projects in Visual Studio 2012. I needed to pull out a bunch of code into their own assemblies so that code could be shared across several projects, all in the same solution. However, no matter what I try, I get warnings for the projects that reference the new shared projects that "All projects referencing {shared project name} must install nuget package Microsoft.Bcl.Build".

I have been over the dependent projects and the shared projects with a fine-tooth comb, verifying in detail that they all use the same version and exact same DLL for the Microsoft.Bcl version 1.0.1.19 and Microsoft.Bcl.Async version 1.0.16 packages:

• System.Runtime

• System.Threading.Tasks

• Microsoft.Threading.Task

• Microsoft.Threading.Tasks.Extensions
• Microsoft.Threading.Tasks.Extensions.Phone

The DLL paths are all resolved and identical. The XAP file does build but I still get that warning telling me that Microsoft.Bcl.Build is not referenced in the dependent projects, despite the fact that I can see that it is.

If I try instead to uninstall and then reinstall those two packages using NuGet for each project involved, I get references with empty paths and the warning icon for the 5 DLL references involved. For some reason NuGet adds the references but can't find the DLLs. Also, if I do this, I find myself with the problem frequently of having projects where I get the "Can't add reference" error when trying to add a reference. Then I have close and re-open the solution, and that leads to a "project failed to load" error. So I have to edit the project file manually, remove the faulty package import statements, and reload the project.

How can I fix this problem and what is the general technique for avoiding this headache in the future? Letting NuGet manage missing packages didn't help at al.

Answer 1

In case anyone else comes across this and @Swell's solution made you go "wtf":

I recently went through an older MVC project and updated it (updated razor, asp, http, etc. nuget packages). The project, independent of itself, built fine, but when i went to publish it failed with the OP's errors.

It turns out it's because I didn't update the *.Tests project associated with it (should have figured, though not sure why Tests is that closely tied to the project). So, to fix:

1. Right-click the Solution and manage nuget packages.
2. Go through all the packages that were updated in the web project and apply them to the other projects as well (each "Update" will display a tree with the applicable projects, I was fine just OKAY-clicking through).
3. Rebuild.

You should now be good and it shouldn't bark at you. Hope that helps others.