Hi,

The clone method of eieio-instance-inheritor sets the slots of the new
objects. For example:

   
   (defclass A (eieio-instance-inheritor)
     ((foo
       :initarg :foo
       :initform "something")))
   
   (defvar a (A))
   (defvar b (clone a))
   (slot-boundp b :foo) ; => t

This is in contrast to the doc which says "All slots are unbound, except those
initialized with PARAMS". The original eieio implementation initialized the
objects with unbound values like this:

╭──────── #68 ─ emacs-source/lisp/emacs-lisp/eieio-base.el ──
│   (let ((nobj (make-vector (length obj) eieio-unbound))
╰──────── #68 ─

The current implementation dispatches to cl-call-next-method. I am attaching a
patch which preserves the call to cl-call-next-method.

  Vitalie