The *tracenable* system variable controls whether or not the
(defun foo (x) (fee x))   ; define FOO
(defun fee (y) (break))   ; define FEE
(setq *tracenable* T)     ; enable the back trace
(setq *tracelimit* NIL)   ; show all the entries
(foo 5)                   ; break: **BREAK**
                          ; prints  Function:#<Subr-BREAK...>
                          ;         Function:#<Closure-FEE...>
                          ;         Arguments:
                          ;           5
                          ;         Function:#<Closure-FOO...>
                          ;         Arguments:
                          ;           5
(clean-up)                ; from break loop
(setq *tracelimit* 2)     ; show only 2 entries
(foo 5)                   ; break: **BREAK**
                          ; prints  Function:#<Subr-BREAK...>
                          ;         Function:#<Closure-FEE...>
                          ;         Arguments:
                          ;           5
(clean-up)                ; from break loop
Note: *tracenable* and
*tracelimit* system variables have to do
with back trace information at entry to a
See the
*tracenable*
system variable in the