I got this workaround on debian wheezy when using distribution codename: Get "python-apt" and "unattended-upgrades" packages from experimental and install them manually.
When I typed this they were python-apt_0.8.9~exp2_amd64.deb and unattended-upgrades_0.80~exp2_all.deb -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

