I'm running the latest CVS version of slime, "2009-05-19" in a fairly recent CCL (OpenMCL), "Version 1.3-r11936 (DarwinX8664)". I would expect the following code to bring up an SLDB buffer with a break loop in the repl: (setq *break-on-signals* t) (handler-case (error "foo") (error () 1)) Instead, it returns 1. This is not surprising given this in swank-openmcl.lisp: (defun break-in-sldb (x y &rest args) (let ((*sldb-stack-top-hint* (or *sldb-stack-top-hint* (ccl::%get-frame-ptr)))) (apply #'cerror y (if args "Break: ~a" x) args))) I'm debugging some server code that really needs to catch all errors. This makes it rather difficult. The only workaround I've discovered is to set swank-backend::*break-in-sldb* to NIL and use CCL's builtin debugger. Not my favorite debugging environment. Clues, anyone? I could probably fix this myself, and if nobody else has done it, I may be forced to, but I'd rather make progress on my application code. -Bill