I think the kind of "unreliability" in question is, for example, when a
process starts and unlinks itself. I doubt Emacs will ever do this. Using
the proc file system is "technically" unreliable, unable to cover 100% of
all potential cases, but is practically reliable, especially in this case.

On Tue, Sep 17, 2024 at 3:07 PM Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Ship Mints <shipmints@gmail.com>
> > Date: Tue, 17 Sep 2024 14:14:54 -0400
> > Cc: Spencer Baugh <sbaugh@janestreet.com>, 73318@debbugs.gnu.org,
> larsi@gnus.org,
> >       acorallo@gnu.org
> >
> > Google's build system, gn, used for Chromium, et.al., has support for
> this which can provide some inspiration
> > for most of the major platforms on which Emacs runs; qv
> > https://gn.googlesource.com/gn/+/refs/heads/main/src/util/exe_path.cc
>
> Thanks.  That's exactly the method that I was told was unreliable on
> GNU/Linux.  I don't know enough to argue with people who said that
> about this particular feature.
>