Bug#934491: libelogind0: failing to switch from systemd to sysvinit-core/elogind results in libsystemd.so.0 disappearing

[Mark Hindley]

Thanks for everybody's input with this thorny issue.

I am now wondering if the prime responsibliity for the system breakage here is
down to apt's behaviour.

On Sun, Aug 11, 2019 at 03:31:00PM +0100, Simon McVittie wrote:
> Actual result (transcript below):
> 
> * systemd-sysv is removed
> * sysvinit-core is unpacked
> * systemd is also removed
> * systemd's prerm fails because it is still the active init system
>   (this check is present since Debian systemd commit c3f5f249 in 44-6,
>   released in 2012 - it appears the intention is that anyone wishing to
>   switch from systemd to sysvinit should replace systemd-sysv with
>   sysvinit-core, then reboot into sysvinit, and only (auto)remove
>   systemd after that reboot)

At this point apt has failed to remove systemd/241-7 which depends on libsystemd
(=241-7). Surely it should not then go on to try and remove the systemd
dependency? libelogind0 provides libsystemd0 (=241.3) so could never satisfy
that requirement.

> * libsystemd0 is removed anyway

That is wrong and breaks systemd, never mind apt…

Am I missing something?

Mark