Then you have built your program incorrectly and not caught the error in a place where you still have context (e. g. `YourProgramException` sub-type that indicates a recoverable error or `Exception` in the case that you're building something where it doesn't matter what the error is, just that an error occurred).

This can also be done with error passing, and is a design failure there too:

    _, ex = perform_batch_operation(on: list_of_data)
    if ex:
        # Oh no, we don't know which entry in the list failed
        # and can't update the appropriate row
        # (This, of course, should be handled in
        # perform_batch_operation, not bubbled up here)

you would have that preserved as a variable in the context of the error no?