希望有人能给我指明正确的方向。
当我执行 do-release-upgrade 时，我收到有关签名的错误。
sudo do-release-upgrade
Checking for a new ubuntu release
Your Ubuntu release is not supported anymore.
For upgrade information, please visit:
http://www.ubuntu.com/releaseendoflife
Err Upgrade tool signature
404 Not Found [IP: 91.189.91.14 80]
Err Upgrade tool
404 Not Found [IP: 91.189.91.14 80]
Fetched 0 B in 0s (0 B/s)
WARNING:root:file 'oneiric.tar.gz.gpg' missing
Failed to fetch
Fetching the upgrade failed. There may be a network problem.
有人知道如何解决这个问题吗？