Variable: *INITIALIZING-INSTANCE*

Source

(defparameter *initializing-instance*
  ;; A hack to paper over some MOP differences.  Maybe a cleaner way
  ;; to solve this would be to write our own method for SHARED-INITIALIZE,
  ;; as suggested by Pascal Costanza.
  ;; See emails of 2006-09-03/04 on rucksack-devel@common-lisp.net.
  nil)