Suppose you are happily coding away, about to finish a new feature on a shiny new product. You attempt to run your code when an ugly exception rears up from the middle of some code that you call, but did not write yourself. You attempt to use your team's version control software to figure out who wrote that code, and what sort of changes have happened to it that might be the source of the problem. Alas, your version control software reveals that Joe, who left the project months ago, wrote the code throwing the exception.
