PACKAGE_VERSION and new get_build_constant interface

[Gavin Smith]

On Sun, Jan 28, 2024 at 12:12:29PM +0100, Patrice Dumas wrote:
> On Sun, Jan 28, 2024 at 12:16:42AM +0000, Gavin Smith wrote:
> > > If there is still a customization variable to access for this, then
> > > I don't see why the name has to be changed.  I haven't had any new 
> > > thoughts
> > > on this since my previous emails on the topic, I'm afraid.  I remember
> > > that not using PACKAGE_VERSION was mainly due to a clash with a symbol
> > > defined by automake or autoconf, which is an implementation problem that
> > > we could try to work around, rather than changing our public interface.
> > > I'll try to propose a change once I've had time to look at it.
> > 
> > Here's the patch to change it back to PACKAGE_VERSION.  I defined macros
> > with the original values using a _CONFIG suffix as you suggested, which
> > is needed in one place in the code (in the argument to bindtextdomain).
> 
> Looks good to me.  I think that there should also be the names with
> _CONFIG prependend available through Texinfo::Common::get_constant() (or
> whatever name is used for this function).  I can add them later on.

I wanted to come back to this issue as, as I remember, there was the
potential to break user's init files:

https://lists.gnu.org/archive/html/bug-texinfo/2023-11/msg00021.html
"ffmpeg documentation no longer builds after Texinfo 7.1 (due to --init-f"
From:   Arsen Arsenović
Date:   Sat, 04 Nov 2023 14:39:32 +0100

https://lists.gnu.org/archive/html/bug-texinfo/2023-11/msg00065.html
Gavin Smith, 12 Nov 2023

https://lists.gnu.org/archive/html/bug-texinfo/2024-01/msg00037.html
Patrice Dumas, 27 Jan 2024

As far as I remember, the conclusion of this issue was that checking
PACKAGE_VERSION would still work as it did before, in init files such
as those discussed in this message:

https://ffmpeg.org//pipermail/ffmpeg-devel/2023-November/316605.html

There was a new interface added, using Texinfo::Common::get_build_constant.
(This is documented in texi2any_api.texi.)

Do you think we should mention get_build_constant in NEWS?  Are there
any other changes for init files that should also be mentioned in
NEWS?