bug#58637: 29.0.50; [Trunk] Native comp doesn't compile anything anymore

[Eli Zaretskii <eliz@gnu.org>]

> From: Jacob Faibussowitsch <jacob.fai@gmail.com>
> Date: Wed, 19 Oct 2022 11:13:06 -0400
> 
> Not sure how to really describe this bug but the TL;DR is that emacs no longer native compiles anything (even though it thinks it is). It appears to have been broken since:
> 
> commit 1a8015b83761f27d299b1ffa45fc045bb76daf8a
> Author: Andrea Corallo <akrl@sdf.org>
> Date:   Sat Oct 15 00:59:55 2022 +0200
> 
>     * Prevent potential native compilation infinite recursions
> 
>     * lisp/emacs-lisp/comp.el (comp-no-spawn): New var.
>     (comp-subr-trampoline-install, comp-final, comp-run-async-workers)
>     (comp--native-compile): Update.
> 
> Checking out the commit immediately before (0954689cb3243e3af4b0c12c08bdcad608fd8433) and everything works. To see the difference this is reproducible via:
> 
> $ git checkout 1a8015b83761f27d299b1ffa45fc045bb76daf8a
> $ make bootstrap
> $ ./src/emacs -Q
> # switch to Async compilation buffer, and you will see many files “compile”
> $ ./src/emacs -Q
> # switch to Async compilation buffer, and you will once again see the same files “compiled"
> $ git checkout 0954689cb3243e3af4b0c12c08bdcad608fd8433
> $ make bootstrap
> $ ./src/emacs -Q
> # switch to Async compilation buffer, and you will see files begin compiled (for real)
> $ ./src/emacs -Q
> # cannot switch to Async compilation buffer, it does not exist because all files properly compiled
> 
> ----------------------------
> 
> On startup emacs appears to native-compiles every file, every time. Checking ~/.emacs.d/eln-cache/29.0.50-<hash> however I see:
> 
> 29.0.50-<hash> $ ll
> subr--trampoline-6c6f6164_load_0.eln
> subr--trampoline-6d616b652d70726f63657373_make_process_0.eln
> subr—-trampoline-*...
> 
> I.e. only the trampoline functions. Furthermore, emacs “compiles” suspiciously quickly, finished all native-comp for some 100+ files in just under 2s. Historically this has taken much longer.
> 
> Under normal circumstances I expect to see:
> 
> 29.0.50-<hash> $ ll
> subr--trampoline-6c6f6164_load_0.eln
> subr--trampoline-6d616b652d70726f63657373_make_process_0.eln
> subr—-trampoline-*…
> cl-lib-8b938900-c76f14d9.eln
> json-a90a1eab-350c449d.eln
> gv-e0cf7478-3ced7662.eln
> url-parse-ee297c9b-39553ec5.eln
> …
> 
> i.e. the compiled eln files for all the others. And indeed reverting to 0954689cb3243e3af4b0c12c08bdcad608fd8433 I once again see those files generated.

Andrea, can you please look into this?