[racket] Metaprogramming with scheme

> > (with-input-from-file "foo.ss"
> > (lambda ()
> >    (parameterize ([error-display-handler (lambda (name . stuff)
> > (printf "Got ~a ~a\n" name stuff))])
> >      (eval-syntax (read-syntax 'foo.ss)))))

Last quoestion. Is there any way  to define error-display-handler to 
printout the back trace even if there are default exception case?

(define (foo a b) (+ a b))
(+ a1 "2")
=> producece exception and error-display-handler extract and print the 
back trace

-
Val.