This is an issue with your network configuration and something which you'll need to resolve before the upgrade can proceed. From VarLogDistupgradeMainlog.txt:
2019-09-27 10:21:46,335 DEBUG url_downloadable: http://bd.archive.ubuntu.com/ubuntu//dists/bionic/Release 2019-09-27 10:21:46,335 DEBUG s='http' n='bd.archive.ubuntu.com' p='/ubuntu//dists/bionic/Release' q='' f='' 2019-09-27 10:22:01,417 DEBUG error from httplib: '<urlopen error [Errno -3] Temporary failure in name resolution>' ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1845590 Title: Error resolving 'archive.ubuntu.com': Temporary failure in name resolution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1845590/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
