Hello systemd maintainers,

TLDR: update-rc.d in unstable and testing ignores the presence of insserv when
systemd is installed. Please drop the Conflicts on insserv from systemd-sysv as
the conflict is no longer needed and poses problems for maintainers of init
systems other than systemd. Please also consider dropping the Conflicts with
startpar.

systemd is Debian's default init system. It is working well on Linux and I have
it running on the machine I'm typing this message on. Because it's the default
init system it is also installed on our CI systems like salsaci or the
autopkgtest runners.  For those of us who are interested in other init systems
(my own motivation is GNU/Hurd where systemd does not work), the Conflicts
relationship of systemd-sysv with insserv poses a problem because we cannot
install insserv without removing the init system of the machine. This matters
because even though I'm interested in different kernels, I still would like to
be able to carry out my work on Linux. It matters outside of my work
environment because our test infrastructure is running Linux and systemd.

The Conflicts relationship was added as part of the solution for bug #1072562
because update-rc.d wrongly runs it even on systems which use systemd to boot.
Since the resolution of #1141215, update-rc.d no longer interacts with insserv
on systems which are using systemd as init.

I propose the following patch to src:systemd:
--- a/debian/control
+++ b/debian/control
@@ -148,10 +148,9 @@ Conflicts: sysvinit-core,
            initscripts,
            orphan-sysvinit-scripts,
            sysv-rc,
-           insserv,
-           startpar,
            bfh-container (<< 20211009-22~),
            molly-guard (<< 0.8.2~),
+Breaks: init-system-helpers (<< 1.69+nmu1),
 Replaces: sysvinit-core,
 Pre-Depends: systemd
 Depends: ${misc:Depends},

I used the Breaks relationship to make sure that systemd-sysv with the
Conflicts on insserv and startpar removed is not accidentally installed on
systems with an older version of init-system-helpers.

Removing the Conflicts would allow autopkgtests for packages like startpar,
runit, openrc and insserv itself to work on debci as well as salsaci. It would
also make it easier to create Hurd chroots on Linux without the inconvenience
of having to create a chroot inside a chroot even though the code is already
running in a disposable VM (but that one runs systemd, for example on salsaci).

Right now, the autopkgtest of, for example, startpar fails like this: