[Chicken-users] problem with callbacks

[Daniel B. Faken]

Hello all,

  My 'foreign-callback-wrapper' doesn't seem to be capturing the local 
environment - is this correct?  (please pardon me if this is obvious - I'm 
a scheme newbie)

An example:
-----------tst.scm-------------
(declare (uses extras))

(let ((foo (make-hash-table)))

#>!
__callback void test_fn(int val)
{
  extern void scm_callback2(int);
  scm_callback2(val);
}
<#

  (print "hello!")
  (clear-hash-table! foo)

  (define-external (scm_callback (int val)) void
    (print "callback-val is " val)
    (print "in callback: foo is " foo)
    )

  (define callback2 
    (foreign-callback-wrapper void "scm_callback2" 
    (int) (lambda (x) (print "callback-val is " x)
                  (print "in callback: foo is " foo))))


  (print "foo is " foo)
  (test_fn 50)
)
-----------------------------
produces this output:
-----------------------------
gloriot2:~/cr/spu/viewpoint/htcam%csc tst.scm
gloriot2:~/cr/spu/viewpoint/htcam%./tst
hello!
foo is #<hash-table>
callback-val is 50
Error: unprintable non-immediate object encountered

tst.scm: 3    make-hash-table
tst.scm: 13   print
tst.scm: 14   clear-hash-table!
tst.scm: 27   print
tst.scm: 28   test_fn
##sys#gc
tst.scm: 23   print
tst.scm: 24   print
in callback: foo is gloriot2:~/cr/spu/viewpoint/htcam%
-------------------------------

(my actual program is of course more complicated)

This fails for 'test_fn()' calling either scm_callback()
or scm_callback2().

thanks for any help!
Daniel