(tagbody 
                  (mapc #'(lambda (installable)
                            (cond
                              ((not (slot-boundp installable 'short-name))
                               (setf (short-name installable) 
                                     (abbreviate-8 (pathname-name (out-file installable)))))
                              ((not (digit-char-p (aref (short-name installable)
                                                        (1- (length (short-name installable))))))
                               (when (> i 9) (go give-up))
                               (setf (aref (short-name installable) (1- (length (short-name installable))))
                                     (format nil "~a" i))
                               (incf i))
                              (t (go give-up))))
                        installables)
                  (go done)
                give-up
                  (error "Can't resolve short-name conflict ~s, perpetrators: ~a"
                         short
                         (mapcar #'(lambda (installable)
                                     (list (out-file installable)
                                           (short-name installable)))  
                                 installables))
                done)