Subject: 27.1; Edebug breaks when using :append in minibuffer-with-setup-hook

From: Clemens <[email-masked]>
Date: Mon, 15 Feb 2021 12:39:40 +0100

When stepping via edebug through

(defun check ()
   (interactive)
   (minibuffer-with-setup-hook
       (:append (lambda () (insert "world")))
     (read-string "Hello ")))

you get "Symbol's function definition is void: :append" error when 
reaching the :append and can't proceed.

     Clemens