I've spent some quality time with debuggers but have come to the conclusion that it is a seductive way to spend time that doesn't necessarily get me there any faster than with printf or equivalent.

Admittedly, I mostly develop with sbcl and slime, so the judiciously place 'break' statement brings you to a stack trace.

Also with sbcl/slime, you can do ESC-. on a function and go to the actual source, even deep within the core of sbcl itself.

Nonetheless, I mostly depend on logging statements and print statements. When I need to go to python, print statements give most of what I need.