issues with aptitude dist-upgrade from etch to lenny

[Henning Glawe <glaweh@debian.org>]

Moin,
seems like in the dist-upgrade from etch to lenny is one very annoying (and
old, AFAIR I hit it already in woody->sarge and sarge->etch) problem: perl is
in an unusable state during the upgrade and causes maintainer scripts to
fail.

I was following way:
- update from etch and etch-security
- change sources.list (lenny instead of etch)
- update-procedure:
    apt-get update
    aptitude install aptitude
    aptitude dist-upgrade

after the system working for a while, maintainer scripts started to fail and
aptitude exited.
the maintainer-script errors were perl-related: the interpreter could not
find modules (all from perl-base) in @INC.
further investigation showed that perl-base was still installed in the
etch-version, while perl itself was from lenny (and of course, the lenny
version was not finding its own versioned modules from perl-base).

i worked around this by installing perl-base from lenny using dpkg.
which also failed due to the dependency loop between perl and perl-base.

dpkg --configure perl perl-base perl-modules

then put the perl back to a usable state (as dependency loops are fine, as
long as dpkg configures all parts of the loop in one call).

Why not merge the three packages into one? the only package saving mirror 
space due to its 'arch:all'iness is perl-modules, which would add 3.2M per
architecture to the mirror network, but is a constant source of troubles with
perl transitions?

Now the dist-upgrade is running on, I'll keep you updated on the progress :)

-- 
c u
henning