Ahoy, I had thought the 'view-source' command only worked at defun-granularity in SBCL, but Christophe just pointed out that it works to the exact expression (like in CMUCL) provided that your code is compiled at (optimize (debug 2)) or higher. Good to know :-) Unofficially you can make (debug 2) the global default with this in your ~/.sbclrc: (setf (cdr (assoc 'sb-c::debug sb-c::*policy*)) 2) -Luke