我安装了 Ubuntu 12.10，大约 1 个月前，我无法从软件中心、突触或终端安装任何程序，也无法更新已安装的软件。以下是软件中心的屏幕截图：
你会看到没有程序的信息，也没有安装底部。（在“软件源”中，选中了多元宇宙源）
命令的日志sudo apt-get upgrade是：
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
命令日志sudo apt-get update如下：
Err http://ir.archive.ubuntu.com quantal InRelease
Err http://ir.archive.ubuntu.com quantal-updates InRelease
Err http://ir.archive.ubuntu.com quantal-backports InRelease
Err http://ir.archive.ubuntu.com quantal-security InRelease
Err http://extras.ubuntu.com quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ir.archive.ubuntu.com quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ir.archive.ubuntu.com quantal-updates Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ir.archive.ubuntu.com quantal-backports Release.gpg
Unable to connect to 127.0.0.1:9050:
Ign https://private-ppa.launchpad.net quantal InRelease
Err http://extras.ubuntu.com quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal InRelease
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ir.archive.ubuntu.com quantal-security Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Err http://ppa.launchpad.net quantal Release.gpg
Unable to connect to 127.0.0.1:9050:
Ign https://private-ppa.launchpad.net quantal Release.gpg
Ign https://private-ppa.launchpad.net quantal Release
Err https://private-ppa.launchpad.net quantal/main amd64 Packages
couldn't connect to host
Err https://private-ppa.launchpad.net quantal/main i386 Packages
couldn't connect to host
Ign https://private-ppa.launchpad.net quantal/main Translation-en_US
Ign https://private-ppa.launchpad.net quantal/main Translation-en
Reading package lists... Done
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-updates/InRelease
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-backports/InRelease
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-security/InRelease
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/alexeftimie/ppa/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/alexmurray/indicator-sensors/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/amith/ubuntutools/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/atareao/atareao/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/debfx/virtualbox/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/indicator-multiload/stable-daily/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/jfi/ppa/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/lucid-bleed/ppa/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/texlive-backports/ppa/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/tualatrix/next/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/flareget-amd64/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/gtk3/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ppa.launchpad.net/videolan/stable-daily/ubuntu/dists/quantal/InRelease
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ir.archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/alexeftimie/ppa/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/alexmurray/indicator-sensors/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/amith/ubuntutools/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/atareao/atareao/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/debfx/virtualbox/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/indicator-multiload/stable-daily/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/jfi/ppa/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/lucid-bleed/ppa/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/texlive-backports/ppa/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/tualatrix/next/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/flareget-amd64/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/upubuntu-com/gtk3/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch http://ppa.launchpad.net/videolan/stable-daily/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050:
W: Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/motorbike/ubuntu/dists/quantal/main/binary-amd64/Packages couldn't connect to host
W: Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/motorbike/ubuntu/dists/quantal/main/binary-i386/Packages couldn't connect to host
W: Some index files failed to download. They have been ignored, or old ones used instead.
在更新管理器中，当我想检查更新时，它显示：
无法下载以下软件包：
Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal/InRelease Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-updates/InRelease Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-backports/InRelease Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-security/InRelease Failed to download http://extras.ubuntu.com/ubuntu/dists/quantal/InRelease Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050: Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg Unable to connect to 127.0.0.1:9050: Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg Unable to connect to 127.0.0.1:9050: Failed to download http://extras.ubuntu.com/ubuntu/dists/quantal/Release.gpg Unable to connect to 127.0.0.1:9050: Failed to download http://ir.archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg Unable to connect to 127.0.0.1:9050:
请帮忙。
PS我已经看过了更新管理器无法获取更新，但这对我没有帮助，所以请不要将此问题标记为重复
答案1
看来你已经设置了代理服务器“127.0.0.1:9050”；也许是一些反过滤程序或类似的东西。所以如果你不坚持使用这个代理，打开网络并将代理设置为无（或您需要的任何其他代理）并单击设置系统范围。然后您应该能够使用它sudo apt-get update来更新包列表，然后通过sudo apt-get install或使用 synaptic 或 software-center 安装它们。
如果您坚持使用代理服务器，请首先检查是否可以使用该代理访问互联网（使用 Firefox 或任何其他带有该代理的浏览器并打开网站）。然后在网络并设置系统范围。请记住，如果您的代理需要身份验证，您必须编辑/etc/apt/apt.conf手动归档到类似的东西
Acquire::http::proxy "http://username:password@proxy:port";
Acquire::https::proxy "https://username:password@proxy:port";
Acquire::ftp::proxy "ftp://username:password@proxy:port";