尝试从 Ubuntu Server 19.10（在树莓派上）升级到 20.04 - 最后出现以下错误：
Error during update
A problem occurred during the update. This is usually some sort of
network problem, please check your network connection and retry.
E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal-updates/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal-security/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Some index files failed to
download. They have been ignored, or old ones used instead.
完整输出：
ubuntu@malbun:~$ 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
0% [Working]
0% [Connecting to archive.ubuntu.com]
0% [Connecting to archive.ubuntu.com (91.189.88.152)]
0% [Connected to archive.ubuntu.com (91.189.88.152)]
0% [Waiting for headers]
Get:1 Upgrade tool signature [1,554 B]
99% [1 1,554 B/1,554 B 100%]
99% [Working]
99% [Waiting for headers]
Get:2 Upgrade tool [1,341 kB]
0% [2 8,443 B/1,341 kB 0%]
100% [Working]
Fetched 1,343 kB in 0s (0 B/s)
authenticate 'focal.tar.gz' against 'focal.tar.gz.gpg'
extracting 'focal.tar.gz'
screenrc: log: window required
Reading cache
Checking package manager
...
...
...
...
...
Error during update
A problem occurred during the update. This is usually some sort of
network problem, please check your network connection and retry.
E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal-updates/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Failed to fetch
http://us.archive.ubuntu.com/ubuntu/dists/focal-security/main/binary-arm64/Packages
404 Not Found [IP: 91.189.91.39 80], E:Some index files failed to
download. They have been ignored, or old ones used instead.
Restoring original system state
Reading state information... Done
=== Command detached from window (Mon Jan 25 11:30:11 2021) ===
答案1
我遇到了同样的问题一个星期了，似乎在升级时它会从“错误”的存储库中获取信息（http://us.archive.ubuntu.com/）我不知道如何将此目的地更改为http://ports.ubuntu.com这是当前包含 Fossa arm64 软件包的存储库。我还尝试更改位于 的 URL /etc/update-manager/meta-release，该 URL 在升级过程中用于获取新镜像，但没有成功，因为内容 URL 重定向到发行版列表，每个发行版都有其对应的发行版 URL，例如 Focal Fossa：
Dist: focal
Name: Focal Fossa
Version: 20.04.1 LTS
Date: Thu, 23 April 2020 20:04:00 UTC
Supported: 1
Description: This is the 20.04.1 LTS release
Release-File: http://archive.ubuntu.com/ubuntu/dists/focal-updates/Release
ReleaseNotes: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/ReleaseAnnouncement
ReleaseNotesHtml: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/ReleaseAnnouncement.html
UpgradeTool: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/focal.tar.gz
UpgradeToolSignature: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/focal.tar.gz.gpg```