bug#71292: 30.0.50; macOS: .elns have no debug info

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: 71292@debbugs.gnu.org, Andrea Corallo <acorallo@gnu.org>
> Date: Sun, 02 Jun 2024 07:41:13 +0200
> 
> > This should be reported to the GCC and libgccjit folks.  The most
> > probable cause is incorrect DWARF debug info emitted by the compiler.
> > Alternatively, it could be that LLDB interprets the debug info
> > incorrectly.  I sometimes see similar problems when debugging Emacs,
> > especially in optimized versions: arguments in function calls are
> > shown in reverse order, which of course is bogus, since the code
> > works as expected.
> 
> After reading the GCC "how to report a bug" advice, I don't think I can
> produce something useful for them in any reasonable time frame.
> 
> The jit people will also not be of great help I'm afraid. There seems to
> be no one in the know using macOS :-).

I think you should still report that, as best as you can and could
afford to.  It is way better than keeping the information here or to
yourself.  Maybe someone will pick up the gauntlet.  Or not.

> BTW, I'm now using the attached change in my Emacs, which allows me to
> set native-comp-debug, -speed, and -driver-options via environment
> variables. Maybe that's something for Andrea (CC'd).

In general, I don't like using environment variables for this, because
they are passed to sub-processes as well, something you don't
necessarily want.