我已经安装了 Steam Beta，当我运行：
sudo apt-get update
我得到了以下输出：
Ign http://security.ubuntu.com vivid-security InRelease
Ign http://gb.archive.ubuntu.com vivid InRelease
Ign http://ppa.launchpad.net vivid InRelease
Ign http://archive.canonical.com vivid InRelease
Ign http://gb.archive.ubuntu.com vivid-updates InRelease
Get:1 http://security.ubuntu.com vivid-security Release.gpg [933 B]
Hit http://ppa.launchpad.net vivid Release.gpg
Hit http://archive.canonical.com vivid Release.gpg
Ign http://gb.archive.ubuntu.com vivid-backports InRelease
Get:2 http://security.ubuntu.com vivid-security Release [63.5 kB]
Hit http://ppa.launchpad.net vivid Release
Hit http://gb.archive.ubuntu.com vivid Release.gpg
Hit http://archive.canonical.com vivid Release
Get:3 http://gb.archive.ubuntu.com vivid-updates Release.gpg [933 B]
Hit http://gb.archive.ubuntu.com vivid-backports Release.gpg
Hit http://gb.archive.ubuntu.com vivid Release
Get:4 http://gb.archive.ubuntu.com vivid-updates Release [63.5 kB]
Hit http://ppa.launchpad.net vivid/main amd64 Packages
Hit http://archive.canonical.com vivid/partner Sources
Hit http://ppa.launchpad.net vivid/main i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports Release
Hit http://ppa.launchpad.net vivid/main Translation-en
Get:5 http://security.ubuntu.com vivid-security/main Sources [29.9 kB]
Hit http://gb.archive.ubuntu.com vivid/main Sources
Hit http://archive.canonical.com vivid/partner amd64 Packages
Hit http://repo.steampowered.com precise InRelease
Hit http://archive.canonical.com vivid/partner i386 Packages
Get:6 http://security.ubuntu.com vivid-security/restricted Sources [28 B]
Hit http://gb.archive.ubuntu.com vivid/restricted Sources
Hit http://archive.canonical.com vivid/partner Translation-en
Get:7 http://security.ubuntu.com vivid-security/universe Sources [13.2 kB]
Hit http://gb.archive.ubuntu.com vivid/universe Sources
Get:8 http://security.ubuntu.com vivid-security/multiverse Sources [1,957 B]
Hit http://gb.archive.ubuntu.com vivid/multiverse Sources
Get:9 http://security.ubuntu.com vivid-security/main amd64 Packages [87.5 kB]
Hit http://gb.archive.ubuntu.com vivid/main amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/restricted amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/universe amd64 Packages
Get:10 http://security.ubuntu.com vivid-security/restricted amd64 Packages [28 B]
Hit http://gb.archive.ubuntu.com vivid/multiverse amd64 Packages
Get:11 http://security.ubuntu.com vivid-security/universe amd64 Packages [43.0 kB]
Hit http://gb.archive.ubuntu.com vivid/main i386 Packages
Hit http://gb.archive.ubuntu.com vivid/restricted i386 Packages
Get:12 http://security.ubuntu.com vivid-security/multiverse amd64 Packages [3,494 B]
Hit http://gb.archive.ubuntu.com vivid/universe i386 Packages
Get:13 http://security.ubuntu.com vivid-security/main i386 Packages [86.8 kB]
Hit http://repo.steampowered.com precise/steam Sources
Hit http://gb.archive.ubuntu.com vivid/multiverse i386 Packages
Get:14 http://security.ubuntu.com vivid-security/restricted i386 Packages [28 B]
Hit http://gb.archive.ubuntu.com vivid/main Translation-en_GB
Get:15 http://security.ubuntu.com vivid-security/universe i386 Packages [43.0 kB]
Hit http://gb.archive.ubuntu.com vivid/main Translation-en
Hit http://gb.archive.ubuntu.com vivid/multiverse Translation-en_GB
Get:16 http://security.ubuntu.com vivid-security/multiverse i386 Packages [3,675 B]
Hit http://gb.archive.ubuntu.com vivid/multiverse Translation-en
Get:17 http://security.ubuntu.com vivid-security/main Translation-en [44.9 kB]
Hit http://gb.archive.ubuntu.com vivid/restricted Translation-en_GB
Hit http://gb.archive.ubuntu.com vivid/restricted Translation-en
Hit http://security.ubuntu.com vivid-security/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid/universe Translation-en_GB
Hit http://security.ubuntu.com vivid-security/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid/universe Translation-en
Get:18 http://gb.archive.ubuntu.com vivid-updates/main Sources [64.6 kB]
Get:19 http://security.ubuntu.com vivid-security/universe Translation-en [27.1 kB]
Hit http://repo.steampowered.com precise/steam amd64 Packages
Get:20 http://gb.archive.ubuntu.com vivid-updates/restricted Sources [28 B]
Get:21 http://gb.archive.ubuntu.com vivid-updates/universe Sources [27.6 kB]
Get:22 http://gb.archive.ubuntu.com vivid-updates/multiverse Sources [1,957 B]
Get:23 http://gb.archive.ubuntu.com vivid-updates/main amd64 Packages [153 kB]
Get:24 http://gb.archive.ubuntu.com vivid-updates/restricted amd64 Packages [28 B]
Get:25 http://gb.archive.ubuntu.com vivid-updates/universe amd64 Packages [84.0 kB]
Hit http://repo.steampowered.com precise/steam i386 Packages
Get:26 http://gb.archive.ubuntu.com vivid-updates/multiverse amd64 Packages [3,494 B]
Get:27 http://gb.archive.ubuntu.com vivid-updates/main i386 Packages [151 kB]
Get:28 http://gb.archive.ubuntu.com vivid-updates/restricted i386 Packages [28 B]
Get:29 http://gb.archive.ubuntu.com vivid-updates/universe i386 Packages [84.0 kB]
Get:30 http://repo.steampowered.com precise/steam Translation-en_GB [151 B]
Get:31 http://gb.archive.ubuntu.com vivid-updates/multiverse i386 Packages [3,675 B]
Hit http://gb.archive.ubuntu.com vivid-updates/main Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/universe Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/main Sources
Hit http://gb.archive.ubuntu.com vivid-backports/restricted Sources
Hit http://gb.archive.ubuntu.com vivid-backports/universe Sources
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse Sources
Hit http://gb.archive.ubuntu.com vivid-backports/main amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/restricted amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/universe amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/main i386 Packages
Get:32 http://repo.steampowered.com precise/steam Translation-en [151 B]
Hit http://gb.archive.ubuntu.com vivid-backports/restricted i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/universe i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/main Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/universe Translation-en
Fetched 1,087 kB in 12s (83.9 kB/s)
W: Failed to fetch gzip:/var/lib/apt/lists/partial/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en%5fGB.gz Invalid file format
W: Failed to fetch gzip:/var/lib/apt/lists/partial/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en.gz Invalid file format
E: Some index files failed to download. They have been ignored, or old ones used instead.
所以我决定再次运行它，这次我在输出中发现了更多错误：
Ign http://ppa.launchpad.net vivid InRelease
Ign http://gb.archive.ubuntu.com vivid InRelease
Ign http://archive.canonical.com vivid InRelease
Ign http://security.ubuntu.com vivid-security InRelease
Hit http://ppa.launchpad.net vivid Release.gpg
Ign http://gb.archive.ubuntu.com vivid-updates InRelease
Hit http://archive.canonical.com vivid Release.gpg
Hit http://security.ubuntu.com vivid-security Release.gpg
Hit http://ppa.launchpad.net vivid Release
Ign http://gb.archive.ubuntu.com vivid-backports InRelease
Hit http://gb.archive.ubuntu.com vivid Release.gpg
Hit http://security.ubuntu.com vivid-security Release
Hit http://archive.canonical.com vivid Release
Hit http://repo.steampowered.com precise InRelease
Hit http://gb.archive.ubuntu.com vivid-updates Release.gpg
Hit http://gb.archive.ubuntu.com vivid-backports Release.gpg
Hit http://gb.archive.ubuntu.com vivid Release
Hit http://gb.archive.ubuntu.com vivid-updates Release
Hit http://gb.archive.ubuntu.com vivid-backports Release
Hit http://ppa.launchpad.net vivid/main amd64 Packages
Hit http://ppa.launchpad.net vivid/main i386 Packages
Get:1 http://repo.steampowered.com precise/steam Sources [151 B]
Hit http://ppa.launchpad.net vivid/main Translation-en
Hit http://archive.canonical.com vivid/partner Sources
Hit http://archive.canonical.com vivid/partner amd64 Packages
Get:2 http://repo.steampowered.com precise/steam amd64 Packages [151 B]
Hit http://archive.canonical.com vivid/partner i386 Packages
Get:3 http://repo.steampowered.com precise/steam i386 Packages [151 B]
Ign http://archive.canonical.com vivid/partner Translation-en
Get:4 http://repo.steampowered.com precise/steam Translation-en_GB [151 B]
Get:5 http://repo.steampowered.com precise/steam Translation-en [151 B]
Hit http://security.ubuntu.com vivid-security/restricted Translation-en
Hit http://security.ubuntu.com vivid-security/main Sources
Hit http://security.ubuntu.com vivid-security/restricted Sources
Hit http://security.ubuntu.com vivid-security/universe Sources
Hit http://security.ubuntu.com vivid-security/multiverse Sources
Hit http://security.ubuntu.com vivid-security/main amd64 Packages
Hit http://security.ubuntu.com vivid-security/restricted amd64 Packages
Hit http://security.ubuntu.com vivid-security/universe amd64 Packages
Hit http://security.ubuntu.com vivid-security/multiverse amd64 Packages
Hit http://security.ubuntu.com vivid-security/main i386 Packages
Hit http://security.ubuntu.com vivid-security/restricted i386 Packages
Hit http://security.ubuntu.com vivid-security/universe i386 Packages
Hit http://security.ubuntu.com vivid-security/multiverse i386 Packages
Hit http://security.ubuntu.com vivid-security/main Translation-en
Hit http://security.ubuntu.com vivid-security/multiverse Translation-en
Hit http://security.ubuntu.com vivid-security/universe Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/main Sources
Hit http://gb.archive.ubuntu.com vivid-backports/restricted Sources
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse Sources
Hit http://gb.archive.ubuntu.com vivid-backports/main amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/restricted amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/main i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/restricted i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/main Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid/main Sources
Hit http://gb.archive.ubuntu.com vivid/restricted Sources
Hit http://gb.archive.ubuntu.com vivid/universe Sources
Hit http://gb.archive.ubuntu.com vivid/multiverse Sources
Hit http://gb.archive.ubuntu.com vivid/main amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/restricted amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/universe amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/multiverse amd64 Packages
Hit http://gb.archive.ubuntu.com vivid/main i386 Packages
Hit http://gb.archive.ubuntu.com vivid/restricted i386 Packages
Hit http://gb.archive.ubuntu.com vivid/universe i386 Packages
Hit http://gb.archive.ubuntu.com vivid/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com vivid/main Translation-en_GB
Hit http://gb.archive.ubuntu.com vivid/main Translation-en
Hit http://gb.archive.ubuntu.com vivid/multiverse Translation-en_GB
Hit http://gb.archive.ubuntu.com vivid/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid/restricted Translation-en_GB
Hit http://gb.archive.ubuntu.com vivid/restricted Translation-en
Hit http://gb.archive.ubuntu.com vivid/universe Translation-en_GB
Hit http://gb.archive.ubuntu.com vivid/universe Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/main Sources
Hit http://gb.archive.ubuntu.com vivid-updates/restricted Sources
Hit http://gb.archive.ubuntu.com vivid-updates/universe Sources
Hit http://gb.archive.ubuntu.com vivid-updates/multiverse Sources
Hit http://gb.archive.ubuntu.com vivid-updates/main amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/restricted amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/universe amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/multiverse amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/main i386 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/restricted i386 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/universe i386 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com vivid-updates/main Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/multiverse Translation-en
Hit http://gb.archive.ubuntu.com vivid-updates/universe Translation-en
Hit http://gb.archive.ubuntu.com vivid-backports/universe Sources
Hit http://gb.archive.ubuntu.com vivid-backports/universe amd64 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/universe i386 Packages
Hit http://gb.archive.ubuntu.com vivid-backports/universe Translation-en
Fetched 755 B in 7s (97 B/s)
W: Failed to fetch http://repo.steampowered.com/steam/dists/precise/steam/source/Sources Hash Sum mismatch
W: Failed to fetch http://repo.steampowered.com/steam/dists/precise/steam/binary-amd64/Packages Hash Sum mismatch
W: Failed to fetch http://repo.steampowered.com/steam/dists/precise/steam/binary-i386/Packages Hash Sum mismatch
W: Failed to fetch gzip:/var/lib/apt/lists/partial/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en%5fGB.gz Invalid file format
W: Failed to fetch gzip:/var/lib/apt/lists/partial/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en.gz Invalid file format
E: Some index files failed to download. They have been ignored, or old ones used instead.
我很害怕再次运行该命令，不知道输出结果会是什么... 所以基本上，我的问题在于，这些错误意味着什么？我应该如何处理它们？
另外需要注意的是，当我遇到这些错误时，Steam 正在运行（并且我已登录）。但注销并完全退出 Steam 似乎没有帮助。
操作系统信息：
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 15.04
Release: 15.04
Codename: vivid
封装信息：
答案1
有时我也能观察到这种情况，但针对的是其他存储库。问题通常会自行解决。
这些文件很容易被破坏。也许它们只是在服务器上重新创建，然后你遇到了不利的情况，或者任何程序员或管理员犯了错误。人都会犯错。
在这种情况下，没有理由成为偏执的熊猫……;)