Breaking init swtich: was Re: sysvinit_3.14-2_source.changes ACCEPTED into experimental

[Mark Hindley]

Lorenzo,

Thanks for highlighting this.

On Sat, Feb 22, 2025 at 05:18:31PM +0100, lorenzo wrote:
> Is this intended?

In short, this wasn't my primary intention, but let's tease out some detail.

Systemd's prerm already refuses removal if systemd is running. There are hacks
around it, but nothing I would recommend in public.

Iain's original submission in #940965 was about forced switch to systemd by apt
not finding a solution with sysvinit. Adding Protected: yes would appear to
prevent such behaviour.

I have just tried switching from sysvinit-core/experimental to runit-init and
the only way that succeeds for me is to use

  DPKG_FORCE=remove-protected dpkg --remove sysvinit-core

followed by

 apt install runit-init

So it is still possible to switch. Views may differ as to if this is too
difficult or dangerous. My personal gut feeling is that switching init on a
system is a rare occurence, so the extra dpkg --force-remove-protected step
isn't a great overhead. Also, people do not wish to discover their init has been
changed 'incidentally' by apt. But I would appreciate hearing other
perspectives.

I also see a possible small benefit.  If individual packages to declared they

 Provides: init
 Protected: yes

the contentious init package could disappear and alternative inits would not
need to convince the systemd maintainers that they achieve whatever standard.

Best wishes

Mark