i can proceede with following steps: -------------------- create the file /etc/update-manager/release-upgrades.d/unauth.cfg as root and add the following.
[Distro] AllowUnauthenticated=yes After upgrade, remove this file. -------------------- but, still interesting why package libgbm1 have authenticating error. here is policy: ------------------- $ apt-cache policy libgbm1 libgbm1: Installed: 10.1.3-0ubuntu0.1 Candidate: 10.1.3-0ubuntu0.1 Version table: *** 10.1.3-0ubuntu0.1 0 500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages 100 /var/lib/dpkg/status 10.1.0-4ubuntu5 0 500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages ------------------- -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1385271 Title: Error authenticating some packages To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/1385271/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs