bug#68083: 30.0.50; Intermittent build failure with native compilation

[Eli Zaretskii]

> From: Aaron Jensen <aaronjensen@gmail.com>
> Date: Fri, 29 Dec 2023 16:07:38 -0500
> Cc: Eli Zaretskii <eliz@gnu.org>, 68083@debbugs.gnu.org, 
>       Jens Schmidt <jschmidt4gnu@vodafonemail.de>
> 
> Just to confirm, adding macroexpand to native-comp-never-optimize-functions 
> allows me to build
> successfully.
> 
> It also looks like comp-delete-or-replace-file can be updated to protect 
> rename-file against
> file-already-exists like it does for Windows. That would also likely solve 
> the problem if you want to be
> able to optimize macroexpand.

Are you sure?  We do that on Windows because Windows doesn't allow us
to delete a file that is open by another program.  That shouldn't
happen on Posix systems, so I think what you see here is due to a race
between checking whether a file exists and renaming it, which is a
different problem.

However, feel free to try the same trick we use on Windows and see
whether it helps.