Bug#1057057: debian-policy: Please make Checksums-Sha1 optional

[Guillem Jover <guillem@debian.org>]

Hi!

On Tue, 2023-11-28 at 14:57:10 -0800, Russ Allbery wrote:
> Dimitri John Ledkov <dimitri.ledkov@canonical.com> writes:
> > Dak currently requires Checksums-Sha1, but I am happy to facilitate in
> > patching dak to make Checksums-Sha1 optional if this bug report is
> > accepted.
> 
> The field is documented as mandatory precisely because DAK requires it,
> which makes it mandatory for Debian packages.  As soon as DAK doesn't
> require it, I'm happy to make it optional (and indeed it would arguably be
> a bug in Policy if it's optional in the archive but Policy claims it's
> mandatory).

I'd like to drop those from .changes and .dsc (among other things),
but demoting these which are currently marked as required to me implies
a major format version bump. And I don't recall ever demoting required
fields, only promoting fields from optional to required.

For .changes, I've got this among other cleanups that would be nice to
do to the format:

  https://wiki.debian.org/Teams/Dpkg/Spec/ChangesFormat2.0

but there did not seem to be much enthusiasm when I proposed this some
time ago:

  https://lists.debian.org/debian-devel/2016/04/msg00326.html

For .dsc, there's the problem that, very confusingly the Format is used
not for the file format, but for the source format, which I think was
a mistake at the time, but here we are, see the .dsc section at:

  https://wiki.debian.org/Teams/Dpkg/TimeTravelFixes

Thanks,
Guillem