Bug#636686: [multiarch] libc should Break perl (<< 5.12.4-2)

[Niko Tyni]

Package: perl
Version: 5.12.4-2

Once perl 5.12.4-2 is in testing, this bug should be reassigned
to eglibc so they can add a Breaks: perl (<< 5.12.4-2) to the
libc* packages.

The background is in #630399; summarizing:

- older perl versions built on a non-multiarch-enabled system break
  when the run time system has multiarch enabled: the ExtUtils::Embed
  module uses $Config{libpth} to find libraries, and if /usr/lib/<triplet>
  is not on that list, packages embedding perl fail to build.

- before 5.12.4-2, /usr/lib/<triplet> would only end up in $Config{libpth}
  if libc + gcc were recent enough on the build system

- the perl build where this first happened varies a lot between
  architectures, so we made a sourceful perl change in 5.12.4-2 to
  force /usr/lib/<triplet> into $Config{libpth} even if not supported
  by libc / gcc yet.

- the Breaks: is needed to make sure partial upgrades from squeeze
  don't end up with a broken combination of a newer libc + older perl.

- my investigations indicate that nothing in perl-base is broken even
  in such a partial upgrade scenario, so it's enough to Break just
  perl.  If this turns out to be incorrect, the situation needs to
  be reconsidered of course.
-- 
Niko Tyni   ntyni at debian.org