When printing structure, printing of slot values doesn't respect print-object method

[alanruttenberg]

(defstruct outside the-inside)

(defstruct inside value)

(defmethod print-object ((o inside) stream)
  (print-unreadable-object (o stream :type t :identity nil)
   (format stream "inside")))

(print (make-outside :the-inside (make-inside)))
;; #S(outside :THE-INSIDE #S(inside :VALUE nil))

(print (outside-the-inside *))
;; #<inside inside>