How do I configure msbuild to ouput the full path of a file when it encounters an error building a VS 2005 solution?

Question

This must be trivial, but I have tried and searched for two days now and can’t figure it out: If file c:\abc\def\foo.cs has an error, I’d like the error message to output the full path, not just foo.cs. How can I do this?

Thanks in advance!