Upgrading libvirt from trusty to cloud/stable/liberty fails

When upgrading libvirt-bin after adding the stable/liberty cloud-ppa, I'm getting this error:

ubuntu@jr2:~$ sudo apt-get install libvirt-bin
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libjs-sphinxdoc libjs-underscore libxen-dev python-py python-virtualenv
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  libvirt0
Suggested packages:
  radvd lvm2
The following packages will be upgraded:
  libvirt-bin libvirt0
2 upgraded, 0 newly installed, 0 to remove and 55 not upgraded.
Need to get 0 B/3307 kB of archives.
After this operation, 2332 kB of additional disk space will be used.
Do you want to continue? [Y/n]
WARNING: The following packages cannot be authenticated!
  libvirt-bin libvirt0
Install these packages without verification? [y/N] y
(Reading database ... 90242 files and directories currently installed.)
Preparing to unpack .../libvirt-bin_1.2.16-2ubuntu10~cloud0_amd64.deb ...
libvirt-bin stop/waiting
stop: Unknown instance:
dpkg: error processing archive /var/cache/apt/archives/libvirt-bin_1.2.16-2ubuntu10~cloud0_amd64.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
libvirt-bin start/running, process 22382
Preparing to unpack .../libvirt0_1.2.16-2ubuntu10~cloud0_amd64.deb ...
Unpacking libvirt0 (1.2.16-2ubuntu10~cloud0) over (1.2.2-0ubuntu13.1.14) ...
Errors were encountered while processing:
 /var/cache/apt/archives/libvirt-bin_1.2.16-2ubuntu10~cloud0_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
ubuntu@jr2:~$ apt-cache policy libvirt-bin
libvirt-bin:
  Installed: 1.2.2-0ubuntu13.1.14
  Candidate: 1.2.16-2ubuntu10~cloud0
  Version table:
     1.2.16-2ubuntu10~cloud0 0
        500 http://ubuntu-cloud.archive.canonical.com/ubuntu/ trusty-updates/liberty/main amd64 Packages
 *** 1.2.2-0ubuntu13.1.14 0
        500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1.2.2-0ubuntu13.1.7 0
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
     1.2.2-0ubuntu13 0
        500 http://nova.clouds.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

This only happen if the package from trusty-updates is installed before adding the cloud PPA. If libvirt-bin is not installed, the installation of the new package works fine.

Expected result: The upgrade of libvirt-bin should work without an error.

Steps to reproduce:
$ apt-get install libvirt-bin
$ echo "http://ubuntu-cloud.archive.canonical.com/ubuntu/ trusty-updates/liberty/main" > /etc/apt/sources.list.d/os.list
$ apt-get update
$ apt-get install libvirt-bin