当我试图从ubuntu 18.04升级到20.04时,我遇到了这个问题:
$sudo do-release-upgrade -d
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [1,554 B]
Err Upgrade tool
404 Not Found [IP: 59.80.44.48 80]
Fetched 1,554 B in 0s (0 B/s)
WARNING:root:file 'focal.tar.gz' missing
Failed to fetch
Fetching the