How to find reason of failed Build without any error or warning

Question

I have a WebApplication which contains reference to WCF services.

While building using Visual Studio 2010, Build fails without any error or warning. However building

Answer 1

I had a similar problem after adding a new project (called "TestCleaner") to my solution: Build failed, no errors.

I increased output verbosity (see Richard J Foster's instructions) and searched the output for "failed". I quickly discovered which project was failing, and why: project "TestRunner" had failed with "error CS0246: The type or namespace name 'TestCleaner' could not be found" (even though no problems were highlighted in the code).

Checking TestRunner's references, sure enough the reference to TestCleaner was marked as unresolved, and the path was missing from the reference properties. Deleting and re-adding didn't fix it. Again, no explanation why.

unresolved reference

I finally discovered the cause: "TestCleaner" was using a different target framework to the other projects. It was .Net 4.5.2; the others were 4.5.