Re: [PATCH 3/3] deb_add_changelog: use SOURCE_DATE_EPOCH

["Moessbauer, Felix" <felix.moessbauer@siemens.com>]

On Mon, 2023-01-09 at 10:25 +0100, Henning Schild wrote:
> Am Mon,  9 Jan 2023 05:14:28 +0000
> schrieb Felix Moessbauer <felix.moessbauer@siemens.com>:
> 
> > In case the SOURCE_DATE_EPOCH bb variable is set, use that value
> > both for the auto-generated changelog as well as when appending to
> > an existing changelog.
> 
> The variable SOURCE_DATE_EPOCH does not make it into the build
> environment and it very likely should not because the overall value
> for
> a single image must not be used for all packages. So we can not and
> should not use it. For a package the sane value would likely be the
> newest changelog entry ... like we try and do already.

I have to disagree. The SOURCE_DATE_EPOCH is only used to create the
timestamp in the debian changelog, as it is the best information we
have. And it is only used when we modify (or create) the changelog.
This is a prime example for what this variable is for: Adding a
timestamp where otherwise no meaningful value is available. Artificial
values are always dangerous.

Inside the sbuild environment, the SOURCE_DATE_EPOCH is defined and
exported by the debhelper scripts and points to the top most changelog
entry. For details, see /usr/share/dpkg/pkg-info.mk
There, indeed the SOURCE_DATE_EPOCH **bitbake** variable is not used
and also should not be used.

Felix

> 
> Henning
> 
> > Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
> > ---
> >  meta/classes/debianize.bbclass | 11 ++++++-----
> >  1 file changed, 6 insertions(+), 5 deletions(-)
> > 
> > diff --git a/meta/classes/debianize.bbclass
> > b/meta/classes/debianize.bbclass index 3531421..49ae0dd 100644
> > --- a/meta/classes/debianize.bbclass
> > +++ b/meta/classes/debianize.bbclass
> > @@ -14,7 +14,7 @@ MAINTAINER ??= "Unknown maintainer
> > <unknown@example.com>" 
> >  deb_add_changelog() {
> >         changelog_v="${CHANGELOG_V}"
> > -       timestamp=3600
> > +       timestamp=${@ d.getVar('SOURCE_DATE_EPOCH', True) or '3600'
> > }
> >         # we have a changelog and that is not autogenerated
> >         # (when autogenerated, changelog.orig is empty)
> >         if [ -f ${S}/debian/changelog ] && [ -s
> > ${WORKDIR}/changelog.orig ]; then @@ -23,9 +23,11 @@
> > deb_add_changelog() { fi
> >                 orig_version=$(dpkg-parsechangelog -l
> > ${WORKDIR}/changelog.orig -S Version) changelog_v=$(echo
> > "${changelog_v}" | sed 's/<orig-version>/'${orig_version}'/')
> > -               orig_date=$(dpkg-parsechangelog -l
> > ${WORKDIR}/changelog.orig -S Date)
> > -               orig_seconds=$(date --date="${orig_date}" +'%s')
> > -               timestamp=$(expr ${orig_seconds} + 42)
> > +               if [ -z "${SOURCE_DATE_EPOCH}" ]; then
> > +                       orig_date=$(dpkg-parsechangelog -l
> > ${WORKDIR}/changelog.orig -S Date)
> > +                       orig_seconds=$(date --date="${orig_date}"
> > +'%s')
> > +                       timestamp=$(expr ${orig_seconds} + 42)
> > +               fi
> >         fi
> >  
> >         date=$(LANG=C date -R -d @${timestamp})
> > @@ -42,7 +44,6 @@ EOF
> >         # prepend our entry to the original changelog
> >         echo >> ${S}/debian/changelog
> >         cat ${WORKDIR}/changelog.orig >> ${S}/debian/changelog
> > -       fi
> >  
> >         if [ -f ${WORKDIR}/changelog ]; then
> >                 latest_version=$(dpkg-parsechangelog -l
> > ${WORKDIR}/changelog -S Version)
>