Trying to `edebug-defun' on `widget-default-create' produces an error.

This is reproducible in today's master (see below for config) as well as
28.2 tag (same config options).

Reproducer:

    ;; -nw or not makes no difference
    $ src/emacs -Q -nw -l lisp/wid-edit.el{,}

    ;; line 1640
    C-s defun widget-default-create RET
    C-u C-M-x

Full backtrace as shown on the error is attached.