Re: `interactive-form` symbol property (was: [Emacs-diffs] emacs-26 9a53b6d: Say how to override a primitive interactive spec)

[Radon Rosborough]

> You can't advise a function that doesn't exist yet.

Actually, you can. Check it out:

    (advice-add #'nonexistent-function :before
                (lambda ()
                  (message "The advice works!")))

    (defun nonexistent-function ()
      (message "The original function was called."))

    (nonexistent-function)