/etc/profile.d/upstart-phablet.sh sets UPSTART_SESSION to null value

[James Hunt]

Script /etc/profile.d/upstart-phablet.sh sets XDG_RUNTIME_DIR to a suitable value, then calls:

export UPSTART_SESSION=$(/sbin/initctl list-sessions | awk '{ print $NF; quit }')

However, "sudo su -" does not result in the creation of XDG_RUNTIME_DIR for the root user, hence UPSTART_SESSION is set to the null value.

This leads to confusing upstart behaviour:

phablet@ubuntu-phablet:~$ sudo su -
initctl: unable to determine sessions
root@ubuntu-phablet:~# initctl list
initctl: Unable to connect to Upstart: Empty address ''
root@ubuntu-phablet:~# unset UPSTART_SESSION
root@ubuntu-phablet:~# initctl list | head
cgroup-lite start/running
mountall-net stop/waiting
mountnfs-bootclean.sh start/running
passwd stop/waiting
rc stop/waiting
rsyslog start/running, process 437
startpar-bridge stop/waiting
tty4 stop/waiting
udev start/running, process 631
upstart-udev-bridge start/running, process 624

I think the issue may actually be related to logind not creating XDG_RUNTIME_DIR.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Martin Pitt (pitti)]

> However, "sudo su -" does not result in the creation of XDG_RUNTIME_DIR for the root user, hence UPSTART_SESSION is set to the null value.

That's correct, and intended. This was explicitly done in https://launchpad.net/ubuntu/+source/systemd/204-0ubuntu19.1 for bug 1197395. $XDG_RUNTIME_DIR must *never* be set for a session/program which does not belong to the owner of /run/user/..., in particular not root. Otherwise processes from root will damage/destroy the user's runtime dir.