Best Books / Stories on Debugging

Hi!

I'm about to roll my own tools for debugging _analog_ circuits. I'm hoping to read stories of great tools to give me ideas. Things I've really liked are gdb, valgrind, the lisp machine's / smalltalk's abilities to jump right into the line of code that caused the exception, and some FPGA tricks with jtag.

What are some of the most inspiring debugging tools you know of? Any + all links appreciated.

Thanks!