bug#69872: 29.2; Async native compilation of seq.el test uses up resources and hangs

[Eli Zaretskii]

> Date: Mon, 18 Mar 2024 09:32:24 -0400
> From:  Jon Levin via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> 
> When I update my installed packages on some version of emacs which
> is build with native-compilation enabled, most times I end up
> having to kill emacs and restart it in order to sidestep a problem
> where a single emacs process, seemingly running a compilation step
> (I think) uses 100% of a single virtual core and never completes.
> 
> This is the process responsible:
> 
>   mhcat      12800    6874 99 09:10 pts/96   00:10:41 /usr/bin/emacs 
> -no-comp-spawn -Q --batch --eval (setq w32-disable-abort-dialog t) -l 
> /tmp/emacs-async-comp-seq-tests-znp6r0.el
> 
> I am not sure how to go about reproducing this problem from a
> standing start (emacs -Q) because this seems to be part of an
> otherwise opaque series of steps, and I'm not sure how it starts.
> 
> Perhaps the author of seq.el can help me put together such a test.

seq.el is preloaded, so it is native-compiled only during the build,
and should not be compiled when you update your packages.  I think
what you see is compilation of seq-tests.el, not seq.el, and if that
is the case, the question is: why does your Emacs decide to compile
that file?  Could you look through your installed packages and see
which one of them loads seq-tests.el?  Is it possible that you have
seq.el as a separate package, which perhaps Emacs tries to use instead
of the built-in one?