How can I enable tracing in a script?

[Eric Hanchrow]

(recent CVS guile)

When I run the following script, I want to see something like 

    [something 3]
    |  [something 2]
    |  |  [something 1]
    |  |  |  [something 0]
    |  |  |  0
    |  |  1
    |  3
    6

which is what I see when I use the REPL to define `something', and
invoke it.  But I don't.  Am I misunderstanding something?  (Note that
I don't really believe all the cruft in this script is necessary; I
was merely throwing in everything I could think of to get tracing to
work)

    #!/usr/local/bin/guile \
    --debug -e main
    !#

    (use-modules (ice-9 debug))
    (debug-enable 'trace)
    (trace-stack #t)
    (debug-enable 'backtrace)
    (format #t "~s~%" (debug-options))
    (format #t "~s~%" (traps))
    (format #t "~s~%" (evaluator-traps-interface))
    (format #t "~s~%" (list (@@(ice-9 debug)
                             trace-exit)
                            (@@(ice-9 debug) trace-entry)))
    (evaluator-traps-interface `( exit-frame-handler ,(@@(ice-9 debug) 
trace-exit )))
    (evaluator-traps-interface `(apply-frame-handler ,(@@(ice-9 debug) 
trace-entry)))
    (format #t "~s~%" (evaluator-traps-interface))

    (format (current-error-port) "This message appears on the current error 
port.~%")
    (format #t "traced-stack-ids: ~s~%" (@@(ice-9 debug) traced-stack-ids))
    (format #t "trace-all-stacks? ~s~%" (@@(ice-9 debug) trace-all-stacks?))

    (define (something arg)
      (if (not (positive? arg))
          0
        (+ arg (something (- arg 1)))))

    (define (main . args)
      (trace something)
      (something (string->number (list-ref (car args) 1))))
    ;(something 9)

-- 
But users will not now with glad cries glom on to a language that
gives them no more than what Scheme or Pascal gave them.

        -- Guy Steele, 
http://www.sun.com/research/jtech/pubs/98-oopsla-growing.ps