[plt-dev] macro-stepper and expand help function defined with define-for-syntax

If I put my macro in a helper function with define-for-syntax, then the 
macro stepper will not show expansion of anything inside this macro

For example,

(define-for-syntax (f stx)
  (syntax-case stx ()
    ((_ p ...)
     #'(begin p ...))))
(define-syntax my-begin f)
(my-begin (my-begin 1 2))

Macro stepper with standard hiding won't show the expansion of the 
inside `my-begin', or anything I put there. Is this a bug?

Thanks,
Chongkai