Bug#746578: Reasons to keep systemd-sysv as the first alternative
On Thu, 18 Sep 2014 17:14:01 -0700 Cameron Norman <email@example.com> wrote:
> On Thu, Sep 18, 2014 at 2:10 PM, Josh Triplett <firstname.lastname@example.org> wrote:
> > I'm pulling a quote from the bottom of Steve's mail to the top, to call
> > attention to a new and critical point that I didn't see raised anywhere
> > in the debian-devel discussion:
> > On Thu, 18 Sep 2014 12:23:18 -0700 Steve Langasek <email@example.com> wrote:
> >> If we decide that init *should* be automatically changed on upgrade, then
> > (Which I'm assuming from your footnote  that you *are* in favor of?)
> >> the ordering of the dependencies on libpam-systemd is immaterial except in
> >> the specific case that someone has upgraded to (or newly installed) jessie,
> >> selected an init system other than the default, and subsequently installed a
> >> desktop environment on a system that didn't initially have one. In this
> >> case, installing the DE *definitely* should not override the user's
> >> explicit selection of init system.
> > *This* is a point that I haven't seen raised in the entire previous
> > discussion on debian-devel, and I think it's a completely valid point.
> > Personally, in this case, I'd argue that the desirable dependency (which
> > we can't easily express) would be "sysvinit-core ? systemd-shim :
> > systemd-sysv".
> To be more precise, it would be "!systemd-sysv ? systemd-shim :
> systemd-sysv" so that other alternate inits are treated equally.
No, that's not equivalent. Having sysvinit-core installed, since it
only exists in jessie, indicates a system with sysvinit intentionally
and explicitly installed.
That said, as mentioned in my response to Steve's mail, approximating
the dependency with "systemd-shim | systemd-sysv" may suffice *if* it
doesn't break the new-install, upgrade, d-i, or debootstrap cases.
> One question: if `init` and `libpam-systemd` (with the inversed
> dependency) are installed simultaneously on a system with only
> sysvinit installed (i.e. Wheezy), apt would know that systemd-sysv is
> going to be installed (to satisfy init package's dependency) and would
> not install systemd-shim, correct?
That was one of the scenarios I mentioned in my response to Steve's
mail. Someone should actually test that.
- Josh Triplett