Error authenticating some packages while upgrade

ubuntu 14.04 do-release-upgrade, 报错：

Error authenticating some packages while upgrade

解决方案:

vim /etc/update-manager/release-upgrades.d/unauth.cfg
[Distro]
AllowUnauthenticated=yes

安装完成后删除此文件即可。

参考资料:

https://askubuntu.com/questions/425355/error-authenticating-some-packages-while-upgrade