[elpa] packages/rudel/rudel-display.el:40:1:Error: eieio-oref called on a class: rudel-backend-factory

[Mario Lang <mlang@delysid.org>]

Hi.

Now that fsm.el has been fixed (thanks), the elpa elc build fails in the rudel
package.

The problem seems to be in `eieio-oref' which looks a bit strange to me:

(defun eieio-oref (obj slot)
  "Return the value in OBJ at SLOT in the object vector."
  (declare (compiler-macro
            (lambda (exp)
              (ignore obj)
              (pcase slot
                ((and (or `',name (and name (pred keywordp)))
                      (guard (not (memq name eieio--known-slot-names))))
                 (macroexp--warn-and-return
                  (format-message "Unknown slot `%S'" name) exp 'compile-only))
                (_ exp)))))
  (cl-check-type slot symbol)
  (cl-check-type obj (or eieio-object class))
  (let* ((class (cond ((symbolp obj)
                       (error "eieio-oref called on a class: %s" obj)
                       (let ((c (cl--find-class obj)))
                         (if (eieio--class-p c) (eieio-class-un-autoload obj))
                         c))
                      (t (eieio--object-class obj))))
	 (c (eieio--slot-name-index class slot)))
    ...))

I have to admit that I don't grok eieio, but this piece of code looks
suspicious.  Wouldn't the code after the `error' call be dead?

On a somewhat related note, package rudel could use a port to cl-lib and
cl-generic.  Would that be a worthwhile change to make?

-- 
CYa,
  ⡍⠁⠗⠊⠕