$ sudo apt update
...
Ign:6 https://packagecloud.io/AtomEditor/atom/any any InRelease
Err:8 https://packagecloud.io/AtomEditor/atom/any any Release
404 Not Found [IP: 52.8.40.176 443]
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
我该如何解决此更新问题？
AtomEditor 之前安装在该系统中，但在停用后被删除。尽管未出现在 中，但删除似乎并不完整Software & Updates - Other Software。
有一个相关的问题但我无法使用它的答案，因为正如我上面所示，我没有可用于命令的 Atom 的 ppa 路径ppa-purge。
您能否提供解决此问题所需的确切命令？我尝试过这些命令，但都不起作用：
$ sudo ppa-purge [ppa:]https://packagecloud.io/AtomEditor/atom
Updating packages lists
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
Warning: apt-get update failed for some reason
$ sudo ppa-purge [ppa:]packagecloud.io/AtomEditor/atom
Updating packages lists
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
Warning: apt-get update failed for some reason
$ sudo ppa-purge [ppa:]AtomEditor/atom
Updating packages lists
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
Warning: apt-get update failed for some reason
$ sudo ppa-purge ppa:packagecloud.io/AtomEditor/atom
Updating packages lists
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
Warning: apt-get update failed for some reason
$ sudo ppa-purge ppa:AtomEditor/atom
Updating packages lists
E: The repository 'https://packagecloud.io/AtomEditor/atom/any any Release' no longer has a Release file.
Warning: apt-get update failed for some reason
回答：
鉴于所引用的重复问题中没有一个答案回答了我的问题，我认为我的问题不应该被关闭，以便有人可以提供答案。无论如何，我将在这里提供我的问题的答案，希望它能帮助其他面临类似问题的人。
我发现以下遗留文件导致了该问题：
/etc/apt/sources.list.d/atom.list
/etc/apt/sources.list.d/atom.list.save
它们包含在以下过程中查找的说明sudo apt update：
deb [arch=amd64 signed-by=/usr/share/keyrings/atom.gpg] https://packagecloud.io/AtomEditor/atom/any/ any main
适用于“sunset”Atom 软件包。只需删除这些文件即可解决我的问题。
总之，管理旧版软件包更新问题的方法是检查文件夹/etc/apt/sources.list.d/中相应的旧版更新文件，并使用命令将其删除sudo rm。
澄清：上述解决方案适用于 Ubuntu 22.04。对于早期版本，请参阅@ahmedhamdy 的评论。