Bug#889638: lintian: please downgrade build-depends-on-obsolete-package dh-systemd to warning

[Ron <ron@debian.org>]

Package: lintian
Version: 2.5.72
Severity: normal

Hi,

Lintian reports the following for packages which B-D on dh-systemd
E: source: build-depends-on-obsolete-package build-depends: dh-systemd => use debhelper (>= 9.20160709)

However the suggested replacement is not possible to satisfy on Jessie
without a -backports version of debhelper, and not possible to satisfy
on Wheezy at all with what Debian currently distributes.

A note about there being a transition is welcome, but the severity seems
a bit inflated with my "someone who cares about backports of my packages
remaining as trivial as possible" hat on.

It is still safe to B-D on dh-systemd for now in Sid/Buster, that just
pulls in the transitional package which in turn depends on the version
of debhelper which replaces it - so it would be nice to downgrade the
urgency of this for at least one more release cycle.

Especially since all bets are off in later dh compat versions where
the systemd support has changed completely again - it would be nice to
not make it harder than needed for backports, and have an easy canary
for how many packages still need the older systemd support for that.

  Cheers,
  Ron