On Mon, Aug 4, 2025, 10:00 AM Eli Zaretskii <eliz@gnu.org> wrote:

> From: Rudolf Schlatte <rudi@constantly.at>
> Date: Mon, 04 Aug 2025 07:13:42 +0200
>
> Paul Eggert <eggert@cs.ucla.edu> writes:
>
> > It's a matter of priorities. If we want Emacs to be easy to test
> > reproducibly, there's a real need for improvement here. If we think
> > this sort of testing is unimportant, then indeed we should stop this
> > discussion.
>
> You probably are already aware, but (if my understanding is correct) the
> code that is tested with a non-existent or non-writable home directory
> is byte-code interpreted, whereas with a writable home directory the
> code that is run is natively compiled.  So the tests will test something
> subtly different than what end users will run.

Yes, this is another downside of suppressing native compilation in a
build that's supposed to use it in production.

For reproducible testing of anything other than the support of on-demand native compilation, the tester should build two versions of emacs.  The first --with-native-compilation=no, the second with --with-native-compilation=aot.  Then the use of byte- or native code will be deterministic even if HOME doesn't exist.

Lynn