Next steps (was: Successfully switched to sysvinit on buster/Xfce with selected packages from unstable/experimental)

[Jacob Nevins]

I wrote:
> I hope this will let us make an argument to unblock relevant things from
> buster, and/or write working instructions for buster users (which I'll
> talk about in a followup mail).

So, how could this transition be made smoother next time? I want to
write up some instructions at
<http://without-systemd.org/wiki/index.php/How_to_remove_systemd_from_a_Debian_Buster_installation>
(since the current ones are clearly no good for users of desktop
environments).

It feels like there ought to be some kind of recipe of a form like:
 1. Install sysvinit-core and related stuff, breaking 'desktop' stuff
 2. Reboot into sysvinit, 'desktop' stuff not working (perhaps use
    single-user mode)
 3. On console, install elogind and friends (probably uninstall
    libsystemd0 at this point?)
 4. Reboot into working

However, with the current dependencies, I don't see a way to do this, at
least not without uninstalling half the desktop world and reinstalling
it afterward. (However, I still haven't followed how everything fits
together.)

Perhaps the best we can hope for is to manually bodge systemd's prerm,
do the 'apt install', put up with an unclean shutdown on the reboot into
sysvinit, and possibly some post-reboot dpkg --configure on the console?

Presumably it would be possible to avoid the uninstall-a-running-systemd
problem in a new installation with some sort of installer preseed
shenanigans. However, I have no idea how to go about that, it sounds
pretty hard for non-experts -- it would need some pretty explicit
instructions -- and it doesn't help existing installations who want to
switch.

Even if we do manage to get elogind 241.1 into buster, what do we do
about the need for libpam-elogind-compat? That's presumably not likely
to get into buster? Backports?