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

[Eli Zaretskii]

> From: Björn Lindqvist <bjourne@gmail.com>
> Date: Tue, 22 Apr 2025 01:17:00 +0200
> Cc: Eli Zaretskii <eliz@gnu.org>, 77745@debbugs.gnu.org
> 
> > If your build completed successfully, and your installation is
> > correct, the aot eln files for icons and cl-lib should be in the
> > installed native directory and found there along with the others.
> > Are they installed correctly with correct file permissions?  What
> > makes these two different than the other aot files?
> 
> If I build from source with --with-native-compilation=aot then those
> modules are natively compiled and installed. Otherwise they are
> not. In the Arch Linux package of Emacs that I was using they were
> missing.

This is expected.  Without "aot" only the preloaded Lisp files are
natively compiled as part of the build.

> Afact, not natively compiling during compilation shouldn't cause any
> issues. But it somehow does since cl-lib, icons, and warnings appear
> to be loaded before early-init.el.

I'm guessing that this happens because something in your init files
causes Emacs to emit a warning.  When that happens, Emacs loads
warnings.el and its prerequisites (cl-lib and icons), because the
warning commands are autoloaded.  If the corresponding Lisp files
don't have .eln files in the places where Emacs looks for them, Emacs
will launch async native compilation of those files.

> So if you change the path the native compiler uses for caching in
> early-init.el it will recompile these files every time you start
> Emacs.

Yes.

> Btw, the --with-native-compilation option is a bit weird. Shouldn't
> there be two options, one for whether you want to compile Emacs with
> native compilation support and another one for whether you want to
> precompile all Elisp modules?

Maybe I misunderstand you, but we already have that: there's
'--with-native-compilation' and '--with-native-compilation=aot'.