non-essential adduser poses problems to purging packages

[Helmut Grohne <helmut@subdivi.de>]

Hi release team,

Andreas Beckmann does wonderful QA work and recently figured that some
packages use deluser during purge (e.g. #1035494 and #1035495). deluser
is shipped with adduser and adduser used to be practically essential,
becaue apt used to depend on it, but that dependency was removed on my
request. Now apt never was essential to begin with, but having a Debian
installation without apt is a relatively rare thing. So while this was
theoretically buggy at all times, it is now practically observable.

Even if we fix these bugs in the packages, people may still upgrade
their systems and remove them rather than upgrading. Then, once the
upgrade is finished (and adduser is removed), they may consider purging
them and boom things go bad without any way of us fixing those packages.

So fixing these bugs (and probably not removing users in purge) is the
way to go, but this also raises the question of whether we want to limit
the possible damage in trixie by making adduser temporarily essential
for trixie. What do you think?

Of course, I really like small essential and want it gone, but we need
to balance that with possible breakage.

I think this primarily is a decision that belongs to the release
managers with the default choice being "do nothing about it".

Helmut