On Tue 25 Jan 2022, at 03:28, Greg Wooledge <g...@wooledge.org> wrote:
> On Tue, Jan 25, 2022 at 03:06:00AM +0000, Gareth Evans wrote:
>> On Tue 25 Jan 2022, at 03:02, Gareth Evans <donots...@fastmail.fm> wrote:
>> > On Tue 25 Jan 2022, at 02:54, Greg Wooledge <g...@wooledge.org> wrote:
>> >> A google search led me to <https://bugs.archlinux.org/task/47749>
>> >> which says that the /run/utmp file is supposed to be created by
>> >> "tmpfiles", specifically by the instructions in the configuration
>> >> file /usr/lib/tmpfiles.d/systemd.conf .
>> >>
>> >
>> >> On my system, /usr/lib/tmpfiles.d/systemd.conf contains this line:
>> >>
>> >> F! /run/utmp 0664 root utmp -
>> >>
>> 
>> >> Does your system have this file, and if so, does it contain that line?
>> >
>> > Thanks, yes:
>> >
>> > $ sudo cat /usr/lib/tmpfiles.d/systemd.conf | grep utmp
>> > F! /run/utmp 0664 root utmp -
>> 
>> And fwiw (from a comment in the link you provided)
>> 
>> $ sudo journalctl -b _COMM=systemd-tmpfiles
>> -- Journal begins at Sat 2021-08-21 14:27:06 BST, ends at Tue 2022-01-25 
>> 03:04:>
>> -- No entries --
>
> Next thing to check seems to be:
>
> systemctl status systemd-tmpfiles-setup.service

Aha...

systemd-tmpfiles-setup.service - Create Volatile Files and Directories
     Loaded: loaded (/lib/systemd/system/systemd-tmpfiles-setup.service; static)
     Active: active (exited) since Tue 2022-01-25 01:46:52 GMT; 1h 53min ago
       Docs: man:tmpfiles.d(5)
             man:systemd-tmpfiles(8)
    Process: 1340 ExecStart=systemd-tmpfiles --create --remove --boot 
--exclude-prefix=/dev (code=exited, status=73)
   Main PID: 1340 (code=exited, status=73)
        CPU: 20ms

Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of /var/log/journal.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of /var/log/journal.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of 
/var/log/journal/7f684579096949909ba2bfac31e8423e.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of 
/var/log/journal/7f684579096949909ba2bfac31e8423e.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of 
/var/log/journal/7f684579096949909ba2bfac31e8423e.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /run during canonicalization of /run/log/journal.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /run during canonicalization of /run/log/journal.
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of 
/var/log/journal/7f684579096949909ba2bfac31e8423e/sy>
Jan 25 01:46:52 qwerty systemd-tmpfiles[1340]: Detected unsafe path transition 
/ → /var during canonicalization of 
/var/log/journal/7f684579096949909ba2bfac31e8423e/sy>
Jan 25 01:46:52 qwerty systemd[1]: Finished Create Volatile Files and 
Directories.

Googling "Detected unsafe path transition during canonicalization" led me to 

https://bbs.archlinux.org/viewtopic.php?id=260924

where a user sees this error because / is owned by the user rather than root.

Lo and behold

$ stat /

shows this is what has somehow happened.

$ sudo chown root:root /

solves the disappearing /var/run/utmp problem (and fixes who/users) 

There is nothing in bash history to suggest I did this - can/should it happen 
any other way?

Thanks very much for your help Greg.

Gareth


>
> Make sure it hasn't been disabled or masked, I suppose.  The unit file
> contains this command:
>
> ExecStart=systemd-tmpfiles --create --remove --boot --exclude-prefix=/dev
>
> So, I guess make sure yours has that too.  But hopefully you'll discover
> that it's been disabled or something silly like that, and then you can
> just enable it.

Reply via email to