我收到以下错误：
无法初始化包信息
初始化包信息时出现无法解决的问题。
请报告针对“update-manager”软件包的这个错误，并包含以下错误消息：E：源列表 /etc/apt/sources.list（URI 解析）中的第 56 行格式错误、E：无法读取源列表、E：无法解析或打开软件包列表或状态文件。
我知道问题在于源列表中的第 56 行但我做了“如何从我的 sources.list 中删除格式错误的行？“因为它是我第一个问题的‘[重复]’，但即使提出了每个解决方案，问题仍然存在，我还能做什么？
当我在终端中输入时，gksu gedit /etc/apt/sources.list我得到：
# deb cdrom:[Ubuntu 12.10 _Quantal Quetzal_ - Release i386 (20121017.2)]/ quantal main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://mx.archive.ubuntu.com/ubuntu/ quantal main restricted
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://mx.archive.ubuntu.com/ubuntu/ quantal-updates main restricted
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://mx.archive.ubuntu.com/ubuntu/ quantal universe
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal universe
deb http://mx.archive.ubuntu.com/ubuntu/ quantal-updates universe
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://mx.archive.ubuntu.com/ubuntu/ quantal multiverse
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal multiverse
deb http://mx.archive.ubuntu.com/ubuntu/ quantal-updates multiverse
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://mx.archive.ubuntu.com/ubuntu/ quantal-backports main restricted universe multiverse
deb-src http://mx.archive.ubuntu.com/ubuntu/ quantal-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu quantal-security main restricted
deb-src http://security.ubuntu.com/ubuntu quantal-security main restricted
deb http://security.ubuntu.com/ubuntu quantal-security universe
deb-src http://security.ubuntu.com/ubuntu quantal-security universe
deb http://security.ubuntu.com/ubuntu quantal-security multiverse
deb-src http://security.ubuntu.com/ubuntu quantal-security multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu quantal partner
# deb-src http://archive.canonical.com/ubuntu quantal partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu quantal main
deb-src socio http://archive.canonical.com/ precisa
deb-src http://extras.ubuntu.com/ubuntu quantal main
显然，我必须说我对此还很陌生，所以我将感谢您的帮助。
感谢 -伊莱亚·卡根- 教我如何把'来源列表“这正是我最初想做的事，但我不知道该怎么做，非常感谢。
答案1
消除最后一行之前的内容：
deb-src socio http://archive.canonical.com/ precisa
似乎您手动编辑了它并犯了错误。此行没有指示任何具体内容（main、partner等），所以我不知道此行应该是什么。
删除并保存文件后，更新软件包源，例如sudo apt-get update，或单击查看在系统更新管理器中。
顺便说一句，我不明白更广泛的如何从我的 sources.list 中删除格式错误的行？问题没有涵盖这一点。