bug#22565: Cannot talk to upowerd over D-Bus

[Ricardo Wurmus <rekado@elephly.net>]

Ludovic Courtès <ludo@gnu.org> writes:

> Ricardo Wurmus <rekado@elephly.net> skribis:
>
>> I’m trying to figure out why we cannot use the Xfce menu to shut down or
>> reboot, and while doing that I found that
>>
>>     loginctl poweroff
>>
>> (as root on the TTY) does have the intended effect.  When run as a user
>> I see a similar error as mentioned above:
>>
>>     Failed to power off: Interactive authentication required.
>>
>> I think this is just fine.
>
> I don’t know if it’s fine.  :-)  I would expect that on GNOME/Xfce a
> password window would pop up when that RPC is invoked, but I’m not sure
> how it’s supposed to happen, or under what conditions.

After strace’ing “xfce4-session” when clicking on the shutdown button in
the Xfce menu I see the same error returned over DBus.

xfce4-session sends “PowerOff” to “org.freedesktop.login1” via DBus and
gets “org.freedesktop.DBus.Error.InteractiveAuthorizationRequired” back,
which causes the whole thing to fail.  (I wonder why it doesn’t use the
fallback mechanism to shut down, but maybe that’s because it detected
systemd/logind and committed to shutting down via DBus.)

So maybe it’s not fine after all.

~~ Ricardo