[xml/sgml-pkgs] Bug#705452: docbook-xml: Fail to upgrade due to pre-depend problem

[Helmut Grohne]

On Mon, Apr 15, 2013 at 10:35:22AM +0200, Petter Reinholdtsen wrote:
> The jenkins chroot upgrade testing discovered this problem.  The
> upgrades of several test configurations fail with this message:
> 
>   E: Couldn't configure pre-depend xml-core for docbook-xml, probably a
>     dependency cycle.
> 
> The test configurations
> chroot-installation_squeeze_install_kde_upgrade_to_wheezy,
> chroot-installation_squeeze_install_full_desktop_upgrade_to_wheezy and
> chroot-installation_squeeze_install_kde-full_upgrade_to_wheezy all fail
> with this error message.
> 
> The problem started 2013-04-08 around noon, and the test around noon the
> previous day was OK, so I guess the change triggering this problem was
> introduced that day.

Adam D. Barratt noticed that this coincides with the testing migration
of sgml-base. That migration adds a versioned Pre-Dependency from
sgml-base to wheezy's dpkg.

> I notice that docbook-xml did not change in this period, but neither did
> xml-core, and thus I am not quite sure which package to atribute the
> problem to.  Thus I just pick the one that fail to upgrade according to
> apt-get, and hope someone else is able to figure out exactly what is
> wrong.
> 
> Is docbook-xml involved in some (pre-)dependency loop?
> 
> The failing tests can be reviewed on <URL: http://jenkins.debian.net/ >.
> 
> Setting severity to serious, as this block upgrade from squeeze to
> wheezy for normal KDE desktop users.

Note that
chroot-installation_squeeze_install_developer_upgrade_to_wheezy does not
fail even though it includes docbook-xml. So the issue is more involved.
Even adding the reverse dependency kdoctools of docbook-xml is not
enough.

Note that dpkg has a Pre-Dependency on liblzma5 that causes it to be
upgraded and pulls in multiarch-support forcing a glibc upgrade.

To potential bug squashers with more bandwidth and diskspace than me:

Reducing the set of packages that cause this failure would be great.

To that end I would like to know whether the error also shows when doing
a simulated dist-upgrade. That means adding a "-s" to "apt-get -y
dist-upgrade". That way downloading of the wheezy packages could be
avoided.

>From there successive removal of packages can be used to reduce the
involved package set.

Helmut