Comment 9 for bug 1497420

Specifically, the output is

Rebooting.
systemd 227 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ -LZ4 +SECCOMP +BLKID -ELFUTILS +KMOD -IDN)
Detected virtualization lxc.
Detected architecture x86-64.

Welcome to Ubuntu 16.04!

Set hostname to <adt-xenial.new>.
Failed to install release agent, ignoring: No such file or directory
Failed to create /lxc/adt-xenial/init.scope control group: No such file or directory
Failed to allocate manager object: No such file or directory
[!!!!!!] Failed to allocate manager object, freezing.
Freezing execution.

During that time, I get the following errors:

Nov 09 08:42:31 donald cgmanager[864]: cgmanager: Invalid path /run/cgmanager/fs/none,name=systemd///lxc/adt-xenial/init.scope (No such file or directory)
Nov 09 08:42:31 donald cgmanager[864]: cgmanager:list_children_main: Could not determine the requested cgroup (name=systemd:lxc/adt-xenial/init.scope)
Nov 09 08:42:31 donald cgmanager[864]: cgmanager: Invalid path /run/cgmanager/fs/none,name=systemd///lxc/adt-xenial/init.scope (No such file or directory)
Nov 09 08:42:31 donald cgmanager[864]: cgmanager:list_keys_main: Could not determine the requested cgroup (name=systemd:lxc/adt-xenial/init.scope)
Nov 09 08:42:31 donald lxcfs[882]: ** (process:882): WARNING **: cgmanager method call org.linuxcontainers.cgmanager0_0.ListChildren failed: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: invalid request. Use G_DBUS_DEBUG=message for more info.
Nov 09 08:42:31 donald lxcfs[882]: ** (process:882): WARNING **: cgmanager method call org.linuxcontainers.cgmanager0_0.ListKeys failed: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: invalid request. Use G_DBUS_DEBUG=message for more info.