(use-modules (system vm program) (srfi srfi-1) (ice-9 rdelim) (ice-9 pretty-print))

(define (skip-lines port n)
  (let lp((i 1))
    (cond
     ((= i n) port)
     (else (read-line port) (lp (1+ i))))))

(define (get-src source)
  (let* ((file (source:file source))
         (line (source:line source))
         (fp (any (lambda (x) 
                    (let ((f (string-append x "/" file))) 
                      (if (file-exists? f) (open-input-file f) #f))) %load-path)))
    (skip-lines fp line)
    (let ((src (read fp)))
      (close fp)
      src)))

(define (get-program-src p)
  (let ((source (program-source p 0)))
    (cond
     ((not source) "It's inner procedure implemented with C")
     (else (get-src source)))))

(define (print-src p)
  (pretty-print (get-program-src p)))

reference to undefined identifier: use-modules