Re: Why does signaling an error not call set-message-function?

[Eli Zaretskii]

> From: Mario Lang <mlang@blind.guru>
> Date: Tue, 05 Apr 2022 10:01:58 +0200
> 
> Hi.
> 
> I just realized that only a certain type of message goes through
> `set-message-function'.  In particular, things like
> 
> (signal 'end-of-buffer nil)
> 
> write to the echo area but do not trigger set-message-function.
> 
> This is a bit unexpected.  Is there an equivalent hook for
> error messages going to the echo area?

(set-message-function _does_ affect echo-area messages, just not any
kind of them.)

Are you sure it is a good idea to allow running arbitrary Lisp when
Emacs wants to signal an error?