Re: Undo defalias

[Stefan Monnier via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

> The problem was caused by aggressive-indent-mode.el. It uses
>
> (cl-letf (((symbol-function 'message) #'ignore))
>  ...

So either:
- you're still within the `cl-letf`.  In that case
  `abort-recursive-edit` or some such should fix the problem.
- you're not within the `cl-letf` any more, in which case the question
  becomes: how come `cl-letf` didn't restore the previous value?
  `cl-letf` uses `unwind-protect` so it should restore the previous
  binding reliably even in case of errors.

[ There's admittedly the possibility/risk that you hit `C-g` (or some
  similar error occurred) right at the specific moment when `cl-letf`
  was executing the second part of the `unwind-protect` (i.e. the one
  that reset `message` to its previous definition).
  That's a known hole in our system.  ]


        Stefan