Finding the origin of a Result::Err

Somewhere deep inside a deserialization library I'm using, something returns a Result::Err with a very non-helpful error message. It gets passed on through several layers, some of them macro-generated. When I try to .unwrap() it, I get the location of the .unwrap() call as the origin of the panic. Is there some way to track the location of where the original Result::Err was constructed? This is a third-party library, I do not have the capacity to refactor it to use a more verbose error handling...