Comment 5 for bug 981955

Sorry for the incomplete info

I am using a container without rootfs.
Just type for a not existing container "test":
$ sudo lxc-execute -n test /bin/echo hi
lxc-execute: Invalid argument - failed to get real path for '(null)'
lxc-execute: failed to pin the container's rootfs
lxc-execute: failed to spawn 'test'
lxc-execute: No such file or directory - failed to remove cgroup '/sys/fs/cgroup//lxc/test'

or use a container ceated with:
$ sudo lxc-create -n test
No config file specified, using the default config
'test' created

I used different configs and it seams it is caused by the missing rootfs.

Such simple things worked in the past at least under Natty, but not in precise.