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

[Simon McVittie]

Control: severity -1 minor
Control: tags -1 + wontfix

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. For policykit-1, polkitd is essentially stateless,
so we can just shut it down any time and let D-Bus activation restart it
(with the new home directory) next time it's needed.

But if dbus is installed, then it's very very likely that the system
bus is running (as the messagebus user), and stopping/restarting the
system bus on a running system isn't supported/supportable, so the
practical result is that the home directory cannot be changed by the
maintainer scripts.

Editing the messagebus user's home directory during boot (before the bus
has started) would be sort-of-possible, but seems high-risk: if it somehow
fails, the system will not start up correctly and will be left in a
hard-to-debug state. So I don't think that's a good idea either.

As a result I think this is going to have to just stay as-is forever on
existing installations.

     smcv