After refreshing Squid cache by the commands above the upgrade works normally on both archive.ubuntu.com and ru.archive.ubuntu.com . So it was my personal problems with my squid-deb-proxy server.
I'm sorry for the buzz. ** No longer affects: apache2 (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1888058 Title: Got “Authentication failed” while running do-release-upgrade from 19.10 to 20.04 LTS with proxy configured To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1888058/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
