bug#57562: [PATCH] * lisp/emacs-lisp/comp.el (comp-run-async-workers): Fail more gracefully

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: 57562@debbugs.gnu.org
> Date: Sat, 03 Sep 2022 11:41:14 -0400
> 
> >> > I have trouble seeing the actual change amongst unrelated whitespace
> >> > changes.  Please show a patch with the minimal necessary change,
> >> > without all the reformatting.  Emacs 28.2 is so close to a release
> >> > that playing whitespace and formatting games is not appropriate there.
> >> Hmm... looks like I sent the patch I had on `master`, sorry.
> >> Here is the cleaner `emacs-28` version.
> > So this means we will silently skip native-compilation, leaving an
> > obscure message in a buffer, is that right?
> 
> In *Messages*, I think, yes.

I guess that's enough for Emacs 28.  (And I do wonder how come people
come up with unwritable home directories.)

> > Maybe this is the best we can do for emacs-28 so close to the release,
> > but for master wouldn't it be better to use delayed-warning instead?
> 
> Sounds about right, tho I suspect we might need to do even a bit more on
> `master`, like disabling lazy native compilation when we bump into this
> problem, to avoid repeating that same error message, or trying harder to
> find a writable directory.

I'm more bothered about letting the user know than about working
around the problem.