bug#40774: Error messages shouldn't be hidden when the user is idle

[Eli Zaretskii]

> Date: Wed, 22 Apr 2020 18:21:48 +0000
> From: ndame <ndame@protonmail.com>
> Cc: "40774@debbugs.gnu.org" <40774@debbugs.gnu.org>
> 
> > > The same definition what run-with-idle-timer uses is suitable.
> >
> > Are you sure? That defines when Emacs is idle, which is not the
> > same thing.
> 
> Yes, I meant "user is idle" from Emacs' point of view. I should have
> been more precise. I wrote: "the user is idle (e.g. uses an other app
> or is away from the computer)".
> 
> So this feature comes into play when the user is idle in Emacs,
> e.g. uses an other app, so doesn't look at the Emacs window
> and can miss error messages.

What if the user is looking at another application, and Emacs runs a
prolonged operation of sorts, for example, indexing some large
directory?