Subject: Re: bug#79124: emacs -Q doesn't give me a clean slate

From: Lynn Winebarger <[email-masked]>
Date: Mon, 4 Aug 2025 10:12:09 -0400

On Mon, Aug 4, 2025, 10:00 AM Eli Zaretskii <[email-masked]> wrote:

> > From: Rudolf Schlatte <[email-masked]>
> > Date: Mon, 04 Aug 2025 07:13:42 +0200
> >
> > Paul Eggert <[email-masked]> 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