我正在运行一个 debian (wheezy) Web 服务器，并且我正在定期安装更新。对于该任务，我使用aptitude update后跟aptitude safe-upgrade. 每次执行此过程时，我都会得到此输出，其中包含底部的错误消息：
Hit http://ftp.de.debian.org wheezy Release.gpg
Hit http://ftp.de.debian.org wheezy-updates Release.gpg
Hit http://ftp.de.debian.org wheezy Release
Hit http://ftp.de.debian.org wheezy-updates Release
Hit http://ftp.de.debian.org wheezy/main Sources
Hit http://ftp.de.debian.org wheezy/contrib Sources
Hit http://ftp.de.debian.org wheezy/non-free Sources
Hit http://ftp.de.debian.org wheezy/main amd64 Packages
Hit http://ftp.de.debian.org wheezy/contrib amd64 Packages
Hit http://ftp.de.debian.org wheezy/non-free amd64 Packages
Hit http://ftp.de.debian.org wheezy/contrib Translation-en
Hit http://security.debian.org wheezy/updates Release.gpg
Hit http://ftp.de.debian.org wheezy/main Translation-en
Hit http://security.debian.org wheezy/updates Release
Hit http://security.debian.org wheezy/updates/main Sources
Hit http://ftp.de.debian.org wheezy/main Translation-de_DE
Hit http://security.debian.org wheezy/updates/contrib Sources
Hit http://security.debian.org wheezy/updates/non-free Sources
Hit http://ftp.de.debian.org wheezy/main Translation-de
Hit http://security.debian.org wheezy/updates/main amd64 Packages
Hit http://security.debian.org wheezy/updates/contrib amd64 Packages
Hit http://ftp.de.debian.org wheezy/non-free Translation-en
Hit http://security.debian.org wheezy/updates/non-free amd64 Packages
Hit http://security.debian.org wheezy/updates/contrib Translation-en
Get: 1 http://ftp.de.debian.org wheezy-updates/main Sources [3,855 B]
Hit http://security.debian.org wheezy/updates/main Translation-en
Hit http://security.debian.org wheezy/updates/non-free Translation-en
Get: 2 http://ftp.de.debian.org wheezy-updates/contrib Sources [14 B]
Fetched 3,869 B in 4s (798 B/s)
W: Failed to fetch http://ftp.de.debian.org/debian/dists/wheezy-updates/Release: Unable to find expected entry 'non/source/Sources' in Release file (Wrong sources.list entry or malformed file)
E: Some index files failed to download. They have been ignored, or old ones used instead.
E: Couldn't rebuild package cache
所以我查看了我的源列表，发现这个条目导致了问题：
（这只是我的源列表中的一行）
deb-src http://ftp.de.debian.org/debian/ wheezy-updates main contrib non free
如何更改条目以使其正常工作？这里有安全问题吗？我感谢有关该主题的任何提示和信息。
先感谢您！:-)