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

From: Paul Eggert <[email-masked]>
Date: Tue, 5 Aug 2025 08:23:22 -0700

On 2025-08-05 04:19, Eli Zaretskii wrote:

> AFAIR, you accepted the AOT
> build as a workaround for this problem,

No, I didn't. I rejected it because it's too much of a pain to expect 
users to rebuild Emacs (in an especially-length process!) just to 
reproduce a bug.

> I don't understand how the *.eln files compiled from the *.el files in the
> Emacs source tree are "kosher" when they are in the installation tree,
> but not if they are under ~/.emacs.c/eln-cache/.

I'm assuming that Emacs was installed correctly (if not, all bets are 
off anyway). What I don't want to assume is anything in the user's home 
directory, because that can make tests irreproducible.

>> A reproducible test should not be disrupted merely because the
>> user's ~/.emacs.d/...macroexpand_0.eln is corrupt.
> 
> Why would it be corrupt, but the same file under /usr/lib/emacs cannot
> be?

Could be many reasons. For example, maybe they backed up their home 
directory but then restored it incorrectly. Whatever the reason is, I 
don't want the user's home directory to affect the test.

> The directory where these files live is not important.

It is important, because I want the tests to depend only on the 
installed Emacs, not on the user's own files. That's a core part of 
making tests reproducible.