Re: How to make aot native-compilation and pdmp creation reproduceable

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: bjorn.bidar@thaodan.de,  emacs-devel@gnu.org
> Date: Mon, 09 Oct 2023 13:26:03 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> Offset 17 is the stat of the dump fingerprint (the first 16 bytes are a
> >> magic number).
> >> 
> >> struct dump_header
> >> {
> >>   /* File type magic.  */
> >>   char magic[sizeof (dump_magic)];
> >> 
> >>   /* Associated Emacs binary.  */
> >>   unsigned char fingerprint[sizeof fingerprint];
> >
> > The fingerprint is supposed to remain unchanged if you rebuild the
> > same code base.
> 
> Right, that's the problem -- apparently it isn't unchanged in this case
> as the diff of the executables' objdump shows.
> 
> My hypothesis is that x-win.eln changes between builds (print-circle
> etc.) => make-fingerprint computes a different ingerprint and so on.

If x-win.el didn't change, x-win.eln will not be regenerated, so
something else is at work here.