Bug#757891: init-system-helpers: Please do not depend on perl

[Niko Tyni]

[cc'ing the rsyslog maintainers too]

On Tue, Aug 12, 2014 at 09:02:59AM +0200, Michael Stapelberg wrote:
> Samuel Thibault <sthibault at debian.org> writes:
> > perl is separate from perl-base so that in tight environement, Debian
> > can be installed with only perl-base. A base system installed by d-i,
> > notably, is supposed to only install perl-base, not perl.  It happens
> > however that d-i installs rsyslog, which depends on init-system-helpers,
> > which depends on perl.  Is the whole perl really needed?  If some
> > modules are needed, they could be moved to perl-base, to save having to
> > install the whole perl on all Debian base systems.

> init-system-helpers uses File::Path, File::Basename, File::Find and
> Text::ParseWords — none of them is in perl-base.

(FWIW Text::ParseWords is.)

> Please report back once you’ve made perl-base contain all of them.

I wasn't around when the perl/perl-base split was designed, but my
understanding is that perl-base exists to offer a usable perl interpreter
for maintainer scripts even during upgrades, and for d-i to work. 

It's not blindingly obvious to me that the perl package must not be part
of a "base system installed by d-i", but I can see it would be nice,
particularly as this has apparently been the case until now. OTOH, we
(the perl maintainers) would actually prefer that an end user never
encounters a system without the full perl package, as the split is
somewhat controversial upstream.

 See also https://lists.debian.org/debian-perl/2010/11/msg00021.html

The perl-base package is Essential:yes, so inclusion there is pretty
close to a promise of supporting that interface forever inside the
Essential set.  So care must be taken when adding functionality there.
IMO Perl reimplementations of /usr/bin/find, /usr/bin/basename,
/bin/mkdir -p, and /bin/rm -r don't seem very good candidates.

What's the dependency from rsyslog to init-system-helpers for?
Is there any room for movement there?
-- 
Niko Tyni   ntyni at debian.org