Bug#770025: gcc-4.9-base: please add Breaks: gcc-4.7-base (<< 4.7.3) as in gcc-4.8-base

[Andreas Beckmann <anbe@debian.org>]

On 2014-11-26 07:47, Julien Cristau wrote:
> On Tue, Nov 18, 2014 at 13:13:35 +0100, Andreas Beckmann wrote:
>> I currently face upgrade problrms in piuparts where a minimal chroot
>> keeps gcc-4.7-base installed after a distupgrade (this is taken as a
>> reference), but a chroot with some packages to be tested will remove
>> gcc-4.7-base because gcc-4.8-base gets installed. After removing the
>> packages to be tested the resulting system does not match the
>> reference any more ...
> 
> This doesn't make sense to me, why should gcc-4.7-base be removed?

This should fix most of these upgrade failures:

https://piuparts.debian.org/wheezy2jessie/disappeared_files_after_purge_error.html

2m25.1s ERROR: FAIL: After purging files have disappeared:
  /usr/lib/gcc/x86_64-linux-gnu/4.7/	 not owned
  /usr/share/doc/gcc-4.7-base/	 not owned
  /usr/share/doc/gcc-4.7-base/README.Debian.amd64.gz	 not owned
  /usr/share/doc/gcc-4.7-base/TODO.Debian	 not owned
  /usr/share/doc/gcc-4.7-base/changelog.Debian.gz	 not owned
  /usr/share/doc/gcc-4.7-base/copyright	 not owned
  /var/lib/dpkg/info/gcc-4.7-base:amd64.list	 not owned
  /var/lib/dpkg/info/gcc-4.7-base:amd64.md5sums	 not owned

gcc-4.7-base will be removed if during an upgrade from wheezy to jessie
gcc-4.8-base gets installed. This ill happen in many cases, except when
just upgrading the running apt-get distupgrade in the minimal wheezy chroot
that would only pull in gcc-4.9-base. So lets make the behavior consistent
by adding the same Breaks to gcc-4.9-base.

This does not prevent installation of a newer gcc-4.7-base (from sid) in jessie.

The Breaks in gcc-4.8-base was added according to #736607 to smoothen
upgrade paths from wheezy to jessie and giving apt some incentives to
rather remove some obsolete packages than keeping them installed and
not upgrading a lot of other packages instead. Which has worked really well!


Andreas