Comment 10 for bug 1303891

Dimitri, I've found the issue! The installation of the libselinux1 package during the dist-upgrade from Precise to Trusty causes this issue!

Here are the details from a freshly installed Ubuntu 12.04.4 amd64 VM:
$ sudo apt-get update -qq && sudo apt-get dist-upgrade -qqy
<no output; no updates>

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04.4 LTS"

$ initctl --version
initctl (upstart 1.5)

$ initctl version
init (upstart 1.5)

$ initctl list
avahi-daemon start/running, process 765
...

$ sudo sed -i 's/precise/trusty/g' /etc/apt/sources.list

$ sudo apt-get update -qq
<no ouput; no errors>

$ sudo apt-get install libselinux1 -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  libselinux1
1 upgraded, 0 newly installed, 0 to remove and 1250 not upgraded.
Need to get 58.0 kB of archives.
After this operation, 2,048 B of additional disk space will be used.
Get:1 http://de.archive.ubuntu.com/ubuntu/ trusty/main libselinux1 amd64 2.2.2-1 [58.0 kB]
Fetched 58.0 kB in 0s (330 kB/s)
(Reading database ... 174854 files and directories currently installed.)
Preparing to replace libselinux1 2.1.0-4.1ubuntu1 (using .../libselinux1_2.2.2-1_amd64.deb) ...
Unpacking replacement libselinux1 ...
Setting up libselinux1 (2.2.2-1) ...
Processing triggers for libc-bin ...
ldconfig deferred processing now taking place

New dmesg lines:
[ 256.032898] init: Re-executing /sbin/init

New syslog lines:
Apr 23 14:51:40 test upstart-socket-bridge[1090]: Disconnected from Upstart
Apr 23 14:51:40 test upstart-udev-bridge[595]: Disconnected from Upstart

$ initctl list
avahi-daemon stop/waiting
...