snapd doesn't start in a Ubuntu 14.04 container

[Zygmunt Krynicki]

# On a Ubuntu 20.04 host

lxc launch ubuntu:14.04 trusty
lxc exec trusty -- apt-get update
lxc exec trusty -- apt-get install -y snapd # this fails to start snapd.service

Journal on the container has messages like:

Apr 19 23:02:19 trusty systemd[4263]: Failed at step OOM_ADJUST spawning /usr/lib/snapd/snapd: Permission denied

Commenting out OOMScoreAdjust=-900 from /lib/systemd/upstart/snapd.service fixes the problem

[Miguel Pires (miguelpires1)]

Just pasting here my comment from the duplicate report: The root cause of the issue is in systemd and has been fixed for a long time (https://github.com/systemd/systemd/issues/1611) but 14.04's systemd version is very old and doesn't contain the fix. As mentioned above, you can workaround it by commenting out the "OOMScoreAdjust" line in /lib/systemd/upstart/snapd.service and restarting the snapd service with `systemctl start snapd.service`.