Debugging compiled code is absolutely unpleasant. Fortunately, I only have to do it rarely. From what I can tell, debugging JavaScript that was compiled from CoffeeScript is a standard practice, and I simply don't want to pursue that. It's interesting how you describe CoffeeScript as a tool rather than a language, but in my opinion it is still a very leaky abstraction.

As I mentioned, I look forward to revisiting it when a standard toolset has matured.