[Pkg-utopia-maintainers] Bug#987862: dbus: messagebus homedir out of sync on legacy installations

[Simon McVittie]

On Tue, 04 Mar 2025 at 17:15:08 +0100, Chris Hofstaedtler wrote:
>On Tue, Mar 04, 2025 at 04:04:47PM +0000, Simon McVittie wrote:
>> On Sat, 01 May 2021 at 05:50:04 +0200, Christoph Anton Mitterer wrote:
>> > It seems that previously, the homedir for messagebus used to be /var/run/dbus
>> > while nowadays it is /nonexistent for new installations.
>>
>> Yes.
>>
>> > Could some logic be added to an upcoming version, that all existing installations
>> > are aligned with that?
>>
>> Unfortunately, no, I don't think that's going to be possible.
>> We did a similar transition in src:policykit-1, but we found that usermod
>> will refuse to change the home directory of a user that is currently
>> running any processes.
>
>I'm CCing the adduser maintainer(s), as this seems to be an
>interesting use/edge-case.

Note that usermod is part of passwd (a lower layer than adduser), not
part of adduser.

If I understand correctly, most of the options we pass to adduser only
set its behaviour if it creates our user: if our user already existed,
adduser does not alter it.

We don't currently use sysusers.d in the dbus packaging, but if we did, I
believe it would behave similarly to adduser: if the messagebus user
needed to be created, it would be created with a specified home
directory, but if it already existed, systemd-sysusers would not alter it.

     smcv