Re: [PATCH PING] Honor 'SOURCE_DATE_EPOCH' when generating autoloads.

[Eli Zaretskii <eliz@gnu.org>]

> From: ludo@gnu.org (Ludovic Courtès)
> Date: Sun, 29 Nov 2015 11:44:36 +0100
> 
>   https://lists.gnu.org/archive/html/emacs-devel/2015-11/msg01547.html
> 
> Support bit-for-bit reproducible generation of autoloads.
> See <https://reproducible-builds.org/specs/source-date-epoch/>.
> Submitted on behalf of Alex Kost.
> 
> * lisp/emacs-lisp/autoload.el (autoload-insert-section-header): Check
> whether the 'SOURCE_DATE_EPOCH' environment variable is defined; use it
> as the TIME part of the 'autoloads' sexp when it is.

Thanks, but I think we need to discuss this first.

First, if this is Alex's code, please show his full name and email
address, as they will have to be mentioned in the commit message, and
we need to know the status of his legal paperwork, or the lack
thereof.

Second, I don't see how doing this in only loaddefs.el will help make
an Emacs build "reproducible": each of the *.elc files includes the
version number of the Emacs binary, which is not necessarily constant
across different builds.  (I think I also saw some other stuff in
*.elc files that can be different between otherwise identical builds.)

Then there's the name of the build system and the repository version
string that get hard-coded into the binary.  There could be other
sources of differences.  (I'm not mentioning the C compiler,
assembler, and linker, as I see similar requests posted to the
respective mailing lists.)

Finally, this will have to be documented in the ELisp manual, probably
in the Internals appendix.

Thanks.