执行sudo apt update时出现多个仓库无Release文件的错误，寻求解决方案

看起来你在Ubuntu 22.04（Jammy Jellyfish）上执行sudo apt update时遇到了仓库验证错误，具体的报错信息如下：

E: The repository 'cdrom://Ubuntu 22.04 LTS Jammy Jellyfish - Release amd64 (20220419) jammy Release' does not have 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.

E: The repository 'https://ppa.launchpadcontent.net/gnome3-team/gnome3/ubuntu jammy Release' does not have 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.

E: The repository 'https://ppa.launchpadcontent.net/gnome3-team/gnome3-staging/ubuntu jammy Release' does not have 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.

E: The repository 'https://ppa.launchpadcontent.net/michael-gruz/canon/ubuntu jammy Release' does not have 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.

别担心，这些问题都是因为无效的仓库配置导致的，咱们一步步来解决：

1. 处理CDROM源错误 #

系统安装完成后，默认会保留CDROM安装源，但这个源在日常更新中完全没用，还会触发报错。我们只需要注释掉这个源即可：

• 打开系统源列表文件：

  sudo nano /etc/apt/sources.list
  

• 找到所有以deb cdrom:开头的行，在行首添加#符号注释掉
• 按Ctrl+O保存修改，再按Ctrl+X退出编辑器

2. 移除无效的PPA仓库 #

报错里的几个PPA（gnome3-team/gnome3、gnome3-team/gnome3-staging、michael-gruz/canon）都没有适配Ubuntu 22.04的Release文件，说明它们要么停止维护，要么不支持Jammy版本，直接移除即可。

方法一：用命令快速移除 #

依次执行以下命令：

sudo add-apt-repository --remove ppa:gnome3-team/gnome3
sudo add-apt-repository --remove ppa:gnome3-team/gnome3-staging
sudo add-apt-repository --remove ppa:michael-gruz/canon

方法二：手动删除PPA配置文件 #

如果上面的命令执行有问题，可以手动删除对应的配置文件：

• 进入PPA配置目录：

  cd /etc/apt/sources.list.d/
  

• 删除对应PPA的文件（如果不确定文件名，可以先执行ls查看目录内容）：

  sudo rm gnome3-team-ubuntu-gnome3-jammy.list*
  sudo rm gnome3-team-ubuntu-gnome3-staging-jammy.list*
  sudo rm michael-gruz-ubuntu-canon-jammy.list*
  

3. 验证修复结果 #

完成上面的操作后，重新执行更新命令，应该就不会再报错了：

sudo apt update

备注：内容来源于stack exchange，提问作者Dilshodbek Sobirjonov