Ubuntu 21.10无法安装软件包，ffmpeg安装失败求助

问题背景 #

我尝试安装FFmpeg，常规步骤是：

sudo apt update
sudo apt install ffmpeg

但执行sudo apt update时出现以下错误：

The following signatures were invalid: EXPKEYSIG 277A7293F59E4889 MiKTeX Packager packager@miktex.org
Reading package lists... Done
E: The repository 'http://security.ubuntu.com/ubuntu impish-security 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 'http://gb.archive.ubuntu.com/ubuntu impish 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.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7A3A762FAFD4A51F
E: The repository 'http://gb.archive.ubuntu.com/ubuntu impish-updates 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 'http://gb.archive.ubuntu.com/ubuntu impish-backports 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.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://ctan.dcc.uchile.cl/systems/win32/miktex/setup/deb focal InRelease: The following signatures were invalid: EXPKEYSIG 277A7293F59E4889 MiKTeX Packager packager@miktex.org

执行sudo apt install ffmpeg并确认后，出现404错误：

(base) robbie@ro-rmallett-l1:~$ sudo apt install ffmpeg
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following package was automatically installed and is no longer required:
  libfwupdplugin1
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
  libavdevice58 libdc1394-25 libopenal-data libopenal1 libsdl2-2.0-0
Suggested packages:
  ffmpeg-doc libportaudio2
The following NEW packages will be installed
  ffmpeg libavdevice58 libdc1394-25 libopenal-data libopenal1 libsdl2-2.0-0
0 to upgrade, 6 to newly install, 0 to remove and 19 not to upgrade.
Need to get 3,046 kB of archives.
After this operation, 5,642 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
WARNING: The following packages cannot be authenticated!
  libdc1394-25 libopenal-data libopenal1 libsdl2-2.0-0 libavdevice58 ffmpeg
Install these packages without verification? [y/N] Y
Err:1 http://gb.archive.ubuntu.com/ubuntu impish/universe amd64 libdc1394-25 amd64 2.2.6-3
  404  Not Found [IP: 185.125.190.36 80]
Ign:2 http://gb.archive.ubuntu.com/ubuntu impish/universe amd64 libopenal-data all 1:1.19.1-2
Err:3 http://gb.archive.ubuntu.com/ubuntu impish/universe amd64 libopenal1 amd64 1:1.19.1-2
  404  Not Found [IP: 185.125.190.36 80]
Ign:4 http://gb.archive.ubuntu.com/ubuntu impish-updates/main amd64 libsdl2-2.0-0 amd64 2.0.14+dfsg2-3ubuntu0.1
Ign:5 http://gb.archive.ubuntu.com/ubuntu impish-updates/universe amd64 libavdevice58 amd64 7:4.4.2-0ubuntu0.21.10.1
Ign:6 http://gb.archive.ubuntu.com/ubuntu impish-updates/universe amd64 ffmpeg amd64 7:4.4.2-0ubuntu0.21.10.1
Err:2 http://gb.archive.ubuntu.com/ubuntu impish/universe amd64 libopenal-data all 1:1.19.1-2
  404  Not Found [IP: 185.125.190.36 80]
Err:4 http://security.ubuntu.com/ubuntu impish-updates/main amd64 libsdl2-2.0-0 amd64 2.0.14+dfsg2-3ubuntu0.1
  404  Not Found [IP: 185.125.190.36 80]
Err:5 http://security.ubuntu.com/ubuntu impish-updates/universe amd64 libavdevice58 amd64 7:4.4.2-0ubuntu0.21.10.1
  404  Not Found [IP: 185.125.190.36 80]
Err:6 http://security.ubuntu.com/ubuntu impish-updates/universe amd64 ffmpeg amd64 7:4.4.2-0ubuntu0.21.10.1
  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/pool/universe/libd/libdc1394/libdc1394-25_2.2.6-3_amd64.deb  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/pool/universe/o/openal-soft/libopenal-data_1.19.1-2_all.deb  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/pool/universe/o/openal-soft/libopenal1_1.19.1-2_amd64.deb  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/libs/libsdl2/libsdl2-2.0-0_2.0.14%2bdfsg2-3ubuntu0.1_amd64.deb  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/f/ffmpeg/libavdevice58_4.4.2-0ubuntu0.21.10.1_amd64.deb  404  Not Found [IP: 185.125.190.36 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/f/ffmpeg/ffmpeg_4.4.2-0ubuntu0.21.10.1_amd64.deb  404  Not Found [IP: 185.125.190.36 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

使用--fix-missing参数也无法解决问题，当前系统为Ubuntu 21.10，无法通过APT安装任何新软件包。

解决方法 #

核心原因 #

Ubuntu 21.10（代号Impish Indri）已经终止官方支持（EOL），官方将其源迁移到了归档服务器，原有的gb.archive.ubuntu.com、security.ubuntu.com等地址不再提供该版本的软件包，导致出现404和Release文件缺失错误。此外第三方源（如Spotify、MiKTeX）的密钥过期或失效，也会干扰APT更新。

步骤1：备份原有源配置 #

先备份当前的源列表，防止操作出错：

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
sudo cp -r /etc/apt/sources.list.d /etc/apt/sources.list.d.bak

步骤2：替换官方源为归档源 #

编辑主源文件：

sudo nano /etc/apt/sources.list

将文件中所有的http://gb.archive.ubuntu.com/ubuntu和http://security.ubuntu.com/ubuntu替换为http://old-releases.ubuntu.com/ubuntu。

替换完成后，按Ctrl+O保存，Ctrl+X退出编辑器。

步骤3：清理第三方源（可选但推荐） #

第三方源（如Spotify、MiKTeX）可能因为系统EOL无法正常更新，建议暂时移除这些源以避免干扰：

# 列出所有第三方源文件
ls /etc/apt/sources.list.d/
# 删除对应的源文件，例如：
sudo rm /etc/apt/sources.list.d/spotify.list
sudo rm /etc/apt/sources.list.d/miktex.list

步骤4：更新APT缓存并安装FFmpeg #

执行以下命令更新缓存并安装FFmpeg：

sudo apt update
sudo apt install ffmpeg

额外建议 #

如果条件允许，建议升级到Ubuntu长期支持版本（如22.04 LTS或更高），长期支持版本会提供5年的安全更新和维护，避免类似的源失效问题。

内容的提问来源于stack exchange，提问作者Robbie Mallett