[goto11]

IMHO the purpose of unit tests is to ensure the code is correct and allow you to safely refactor and introduce new functionality without breaking existing behavior. The purpose is not to pinpoint the exact line where the bug is, if a test fails.

What you describe is white-box testing, where the test is coupled to implementation details of a class. This gives you more fine-grained reporting in case of an error but it makes it impossible to refactor the code safely. So I don't think that is a worthy trade-off.

If you often have hard-to-locate bugs in particular large component, the solution is probably to refactor into smaller more loosely-coupled components with well-defined interfaces.