Re: emacs reproducible builds part1 of 2 : eln

[Bernhard M. Wiedemann]

On 11/02/2024 11.24, Andrea Corallo wrote:
> Andrea Corallo <acorallo@gnu.org> writes:
>
> > Stefan Monnier <monnier@iro.umontreal.ca> writes:
> >
> > > > > So, I'm not sure it explains the phenomenon you're seeing (I haven't
> > > > > seen the rest of this thread yet).
> > > >
> > > > Interesting, I imagined the walk order is defined but my question is
> > > > what about two hash table with the same content but created in two
> > > > different sessions?
> > >
> > > Depends how they were filled: if they were filles by the same sequence
> > > of operations, then they should have the same walk-order.
> > > If not, then all bets are off.
> >
> > Okay that's good news, I'll investigate more tomorrow, the case is
> > pretty well defined now so should be possible to understand exactly what
> > is going on.
>
> Okay cool I pushed a fix in emacs29, with that installed we don't try to
> sort anymore conses based on their 'sxhash-equal' value because this is
> not stable over different Emacs sessions.  With the change installed the
> build looks finally reproducible here.
>
> Bernhard please let us know if this solves the problem on your side as
> well.

Thanks for the fix.
I had missed the email and only now got to retest.
I found your commit
614b244a7fa03fcb27d76757e14ef0fa895d6f23
is part of emacs-29.3 and the x-win.el compilation is now deterministic.

The bad news is that there are still 4 more non-deterministic .eln files.
I made a reproducer for one of them:

cd ~/rpmbuild/BUILD/emacs-29.3/native-lisp &&
 for i in $(seq 10) ; do
  ../src/emacs -batch \
  --eval "(batch-native-compile t)" ../lisp/international/utf7.el &&
  md5sum 29.*/utf7.eln
 done | sort | uniq -c

again with ASLR as factor in the result.

The varying files are
emacs/29.3/native-lisp/29.3-f8a6a23e/el-72f9fa70-1a554ff6.eln
emacs/29.3/native-lisp/29.3-f8a6a23e/ox-9aa46d10-040d281c.eln
emacs/29.3/native-lisp/29.3-f8a6a23e/utf7-8aab9346-0cfd2c82.eln
emacs/29.3/native-lisp/29.3-fc431f4a/utf7-8aab9346-0cfd2c82.eln

Unfortunately, the el.el and ox.el don't reproduce non-determinism the 
same way.


And finally there is still part2 left:
.pdmp files have variations from some unknown source.


Ciao
Bernhard M.