Bug#1014115: uninstall does not properly remove enablement symlinks

[Luca Boccassi]

On Thu, 30 Jun 2022 at 15:44, Michael Biebl <biebl at debian.org> wrote:
>
> Am 30.06.22 um 16:32 schrieb Luca Boccassi:
> > On Thu, 30 Jun 2022 at 15:24, Michael Biebl <biebl at debian.org> wrote:
> >>
> >> Am 30.06.22 um 16:13 schrieb Luca Boccassi:
> >>> On Thu, 30 Jun 2022 at 15:08, Michael Biebl <biebl at debian.org> wrote:
> >>>>
> >>>> Am 30.06.22 um 14:26 schrieb Michael Biebl:
> >>>>> This might be a bug in i-s-h, but filing against systemd-homed for
> >>>>> now.
> >>>>>
> >>>>> systemd-homed.service:
> >>>>> [Install]
> >>>>> WantedBy=multi-user.target
> >>>>> Alias=dbus-org.freedesktop.home1.service
> >>>>> Also=systemd-homed-activate.service systemd-userdbd.service
> >>>>>
> >>>>> systemd-homed-activate.service:
> >>>>> [Install]
> >>>>> WantedBy=systemd-homed.service
> >>>>> Also=systemd-homed.service
> >>>>>
> >>>>> → we have a circular dependency here, maybe deb-systemd-helper get's
> >>>>> confused by that
> >>>>
> >>>>
> >>>> I just checked that we can mitigate this issue by removing this circular
> >>>> Also= dependency. It is indeed deb-systemd-helper getting confused by
> >>>> that and as a result not writing proper state files to
> >>>> /var/lib/systemd/deb-systemd-helper.
> >>>> So the damage is already done during installation in postinst.
> >>>> Thus raising to RC to warn users from installing systemd-homed atm.
> >>>>
> >>>> I propose a patch like the attached one, i.e. dropping the Also= from
> >>>> systemd-homed-active.service. WDYT?
> >>
> >> Are you against shipping this patch for the time being until we have a
> >> proper fix?
> >
> > Given the problem is that i-s-h doesn't generate the correct postinst,
> > can we instead add a workaround to the postinst itself?
>
> No, it's not an incorrect postinst. The generated postinst code looks
> fine afaics.
>
> It's deb-systemd-helper failing in postinst [1] (due to the circular
> Also=) and subsequently not writing any state files to
> /var/lib/systemd/deb-systemd-helper (which means it can't clean up the
> state on purge).
>
>
> I'm pasting the error message again, for reference
>
> > Setting up systemd-homed (251.2-7) ...
> > Created symlink /etc/systemd/system/systemd-homed.service.wants/systemd-homed-activate.service -> /lib/systemd/system/systemd-homed-activate.service.
> > Created symlink /etc/systemd/system/dbus-org.freedesktop.home1.service -> /lib/systemd/system/systemd-homed.service.
> > Created symlink /etc/systemd/system/multi-user.target.wants/systemd-homed.service -> /lib/systemd/system/systemd-
> > homed.service.
> > Deep recursion on subroutine "main::get_link_closure" at /usr/bin/deb-systemd-helper line 253, <$fh> line 23.
> > /usr/bin/deb-systemd-helper: error: unable to read /lib/systemd/system/systemd-homed.service
> > Deep recursion on subroutine "main::get_link_closure" at /usr/bin/deb-systemd-helper line 253, <$fh> line 41.
> > /usr/bin/deb-systemd-helper: error: unable to read /lib/systemd/system/systemd-homed-activate.service

I see, then could it be fixed in the postinst manually after the calls
added by the helper?