bug#77745: Async native compilation runs every time I start Emacs

[Eli Zaretskii]

> From: Björn Lindqvist <bjourne@gmail.com>
> Date: Fri, 11 Apr 2025 20:50:17 +0200
> Cc: 77745@debbugs.gnu.org
> 
> > Do you see the *.eln files created each time the native compilation is
> > triggered?  If so, are these files recreated using the same hashes in
> > the file name, or do the hashes change?  Are the sources moved between
> > the sessions, perhaps?  Are you always starting the same Emacs binary,
> > or do you rebuild Emacs between sessions?  Did you customize the value
> > of native-comp-eln-load-path from its default?
> 
> Yes. Same hashes. No. Same binary. Yes! At the top of my init.el I have
> 
>     (setq user-emacs-directory "~/.config/emacs/lisp/")
> 
> causing *most* .eln files to be dumped in
> ~/.config/emacs/lisp/eln-cache/31.0.50-859de2ee.

Why are you setting the value of user-emacs-directory?

> However, two
> mysterious files are still being written to
> ~/.config/emacs/eln-cache/31.0.50-859de2ee (no lisp) in the path:
> 
>     subr--trampoline-6d616b652d70726f63657373_make_process_0.eln
>     subr--trampoline-616c6c2d636f6d706c6574696f6e73_all_completions_0.eln

Probably because that happens before your modified value of
user-emacs-directory becomes in effect.

> If I do not set user-emacs-directory, native-comp-eln-load-path stays
> at its default value and the recompilation problem goes away.

Then please refrain from changing the value of user-emacs-directory.

> As an aside, shouldn't the default native-comp-eln-load-path be
> ~/.cache/emacs/eln-cache? Cache artifacts aren't meant to be generated in
> the configuration hierarchy.

Sorry, I don't understand the question.  What is "the configuration
hierarchy"?