当我使用此命令时sudo apt-get update，输出如下：
Hit http://security.ubuntu.com raring-security Release.gpg
Hit http://us.archive.ubuntu.com raring Release.gpg
Hit http://us.archive.ubuntu.com raring Release
Hit http://security.ubuntu.com precise-security Release.gpg
Hit http://archive.canonical.com raring Release.gpg
Hit http://extras.ubuntu.com raring Release.gpg
Hit http://ppa.launchpad.net raring Release.gpg
Hit http://security.ubuntu.com raring-security Release
Hit http://us.archive.ubuntu.com raring/main Sources
Hit http://security.ubuntu.com precise-security Release
Hit http://us.archive.ubuntu.com raring/restricted Sources
Hit http://archive.canonical.com precise Release.gpg
Hit http://extras.ubuntu.com precise Release.gpg
Hit http://ppa.launchpad.net raring Release.gpg
Hit http://bg.archive.ubuntu.com precise Release.gpg
Hit http://security.ubuntu.com raring-security/main Sources
Hit http://us.archive.ubuntu.com raring/universe Sources
Hit http://archive.canonical.com raring Release
Hit http://security.ubuntu.com raring-security/restricted Sources
Hit http://us.archive.ubuntu.com raring/multiverse Sources
Hit http://extras.ubuntu.com raring Release
Hit http://ppa.launchpad.net raring Release
Hit http://bg.archive.ubuntu.com precise-updates Release.gpg
Hit http://security.ubuntu.com raring-security/universe Sources
Hit http://us.archive.ubuntu.com raring/main amd64 Packages
Hit http://archive.canonical.com precise Release
Hit http://security.ubuntu.com raring-security/multiverse Sources
Hit http://extras.ubuntu.com precise Release
Hit http://us.archive.ubuntu.com raring/restricted amd64 Packages
Hit http://ppa.launchpad.net raring Release
Hit http://bg.archive.ubuntu.com precise Release
Hit http://security.ubuntu.com raring-security/main amd64 Packages
Hit http://us.archive.ubuntu.com raring/universe amd64 Packages
Hit http://archive.canonical.com raring/partner Sources
Hit http://extras.ubuntu.com raring/main Sources
Hit http://security.ubuntu.com raring-security/restricted amd64 Packages
Hit http://us.archive.ubuntu.com raring/multiverse amd64 Packages
Hit http://ppa.launchpad.net raring/main amd64 Packages
Hit http://security.ubuntu.com raring-security/universe amd64 Packages
Hit http://us.archive.ubuntu.com raring/main i386 Packages
Hit http://bg.archive.ubuntu.com precise-updates Release
Hit http://archive.canonical.com raring/partner amd64 Packages
Hit http://extras.ubuntu.com raring/main amd64 Packages
Hit http://security.ubuntu.com raring-security/multiverse amd64 Packages
Hit http://ppa.launchpad.net raring/main i386 Packages
Hit http://us.archive.ubuntu.com raring/restricted i386 Packages
Hit http://security.ubuntu.com raring-security/main i386 Packages
Hit http://us.archive.ubuntu.com raring/universe i386 Packages
Hit http://archive.canonical.com raring/partner i386 Packages
Hit http://bg.archive.ubuntu.com precise/main Sources
Hit http://extras.ubuntu.com raring/main i386 Packages
Hit http://security.ubuntu.com raring-security/restricted i386 Packages
Hit http://us.archive.ubuntu.com raring/multiverse i386 Packages
Hit http://security.ubuntu.com raring-security/universe i386 Packages
Hit http://bg.archive.ubuntu.com precise/restricted Sources
Hit http://security.ubuntu.com raring-security/multiverse i386 Packages
Hit http://us.archive.ubuntu.com raring/main Translation-en
Hit http://bg.archive.ubuntu.com precise/universe Sources
Hit http://ppa.launchpad.net raring/main amd64 Packages
Hit http://archive.canonical.com precise/partner Sources
Hit http://extras.ubuntu.com precise/main Sources
Hit http://ppa.launchpad.net raring/main i386 Packages
Hit http://us.archive.ubuntu.com raring/multiverse Translation-en
Hit http://security.ubuntu.com raring-security/main Translation-en
Hit http://bg.archive.ubuntu.com precise/multiverse Sources
Hit http://archive.canonical.com precise/partner amd64 Packages
Hit http://extras.ubuntu.com precise/main amd64 Packages
Hit http://us.archive.ubuntu.com raring/restricted Translation-en
Hit http://security.ubuntu.com raring-security/multiverse Translation-en
Hit http://bg.archive.ubuntu.com precise/main amd64 Packages
Hit http://archive.canonical.com precise/partner i386 Packages
Hit http://extras.ubuntu.com precise/main i386 Packages
Hit http://us.archive.ubuntu.com raring/universe Translation-en
Hit http://security.ubuntu.com raring-security/restricted Translation-en
Hit http://bg.archive.ubuntu.com precise/restricted amd64 Packages
Hit http://security.ubuntu.com raring-security/universe Translation-en
Hit http://bg.archive.ubuntu.com precise/universe amd64 Packages
Hit http://security.ubuntu.com precise-security/main Sources
Hit http://security.ubuntu.com precise-security/restricted Sources
Hit http://bg.archive.ubuntu.com precise/multiverse amd64 Packages
Hit http://security.ubuntu.com precise-security/universe Sources
Hit http://security.ubuntu.com precise-security/multiverse Sources
Hit http://bg.archive.ubuntu.com precise/main i386 Packages
Hit http://security.ubuntu.com precise-security/main amd64 Packages
Hit http://security.ubuntu.com precise-security/restricted amd64 Packages
Hit http://bg.archive.ubuntu.com precise/restricted i386 Packages
Hit http://security.ubuntu.com precise-security/universe amd64 Packages
Hit http://security.ubuntu.com precise-security/multiverse amd64 Packages
Hit http://security.ubuntu.com precise-security/main i386 Packages
Hit http://bg.archive.ubuntu.com precise/universe i386 Packages
Ign http://us.archive.ubuntu.com raring/main Translation-en_US
Hit http://bg.archive.ubuntu.com precise/multiverse i386 Packages
Hit http://security.ubuntu.com precise-security/restricted i386 Packages
Ign http://us.archive.ubuntu.com raring/multiverse Translation-en_US
Hit http://security.ubuntu.com precise-security/universe i386 Packages
Hit http://security.ubuntu.com precise-security/multiverse i386 Packages
Ign http://us.archive.ubuntu.com raring/restricted Translation-en_US
Ign http://us.archive.ubuntu.com raring/universe Translation-en_US
Hit http://security.ubuntu.com precise-security/main Translation-en
Hit http://security.ubuntu.com precise-security/multiverse Translation-en
Hit http://bg.archive.ubuntu.com precise/main Translation-en
Hit http://security.ubuntu.com precise-security/restricted Translation-en
Hit http://security.ubuntu.com precise-security/universe Translation-en
Hit http://bg.archive.ubuntu.com precise/multiverse Translation-en
Ign http://ppa.launchpad.net raring/main Translation-en_US
Ign http://archive.canonical.com raring/partner Translation-en_US
Ign http://ppa.launchpad.net raring/main Translation-en
Ign http://extras.ubuntu.com raring/main Translation-en_US
Hit http://bg.archive.ubuntu.com precise/restricted Translation-en
Ign http://archive.canonical.com raring/partner Translation-en
Ign http://ppa.launchpad.net raring/main Translation-en_US
Ign http://extras.ubuntu.com raring/main Translation-en
Ign http://archive.canonical.com precise/partner Translation-en_US
Ign http://extras.ubuntu.com precise/main Translation-en_US
Ign http://archive.canonical.com precise/partner Translation-en
Hit http://bg.archive.ubuntu.com precise/universe Translation-en
Ign http://extras.ubuntu.com precise/main Translation-en
Hit http://bg.archive.ubuntu.com precise-updates/main Sources
Ign http://ppa.launchpad.net raring/main Translation-en
Hit http://bg.archive.ubuntu.com precise-updates/restricted Sources
Hit http://bg.archive.ubuntu.com precise-updates/universe Sources
Hit http://bg.archive.ubuntu.com precise-updates/multiverse Sources
Hit http://bg.archive.ubuntu.com precise-updates/main amd64 Packages
Hit http://bg.archive.ubuntu.com precise-updates/restricted amd64 Packages
Hit http://bg.archive.ubuntu.com precise-updates/universe amd64 Packages
Ign http://security.ubuntu.com raring-security/main Translation-en_US
Hit http://bg.archive.ubuntu.com precise-updates/multiverse amd64 Packages
Ign http://security.ubuntu.com raring-security/multiverse Translation-en_US
Hit http://bg.archive.ubuntu.com precise-updates/main i386 Packages
Ign http://security.ubuntu.com raring-security/restricted Translation-en_US
Ign http://security.ubuntu.com raring-security/universe Translation-en_US
Ign http://security.ubuntu.com precise-security/main Translation-en_US
Ign http://security.ubuntu.com precise-security/multiverse Translation-en_US
Hit http://bg.archive.ubuntu.com precise-updates/restricted i386 Packages
Ign http://security.ubuntu.com precise-security/restricted Translation-en_US
Ign http://security.ubuntu.com precise-security/universe Translation-en_US
Hit http://bg.archive.ubuntu.com precise-updates/universe i386 Packages
Hit http://bg.archive.ubuntu.com precise-updates/multiverse i386 Packages
Hit http://bg.archive.ubuntu.com precise-updates/main Translation-en
Hit http://bg.archive.ubuntu.com precise-updates/multiverse Translation-en
Hit http://bg.archive.ubuntu.com precise-updates/restricted Translation-en
Hit http://bg.archive.ubuntu.com precise-updates/universe Translation-en
Ign http://bg.archive.ubuntu.com precise/main Translation-en_US
Ign http://bg.archive.ubuntu.com precise/multiverse Translation-en_US
Ign http://bg.archive.ubuntu.com precise/restricted Translation-en_US
Ign http://bg.archive.ubuntu.com precise/universe Translation-en_US
Ign http://bg.archive.ubuntu.com precise-updates/main Translation-en_US
Ign http://bg.archive.ubuntu.com precise-updates/multiverse Translation-en_US
Ign http://bg.archive.ubuntu.com precise-updates/restricted Translation-en_US
Ign http://bg.archive.ubuntu.com precise-updates/universe Translation-en_US
Reading package lists...
然后sudo apt-get dist-upgrade。我有这个输出：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
lightdm
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
然后我运行这个命令sudo apt-cache policy lightdm，得到以下输出：
lightdm:
Installed: 1.6.0-0ubuntu2
Candidate: 1.6.0-0ubuntu3.1
Version table:
1.6.0-0ubuntu3.1 0
500 http://security.ubuntu.com/ubuntu/ raring-security/main amd64 Packages
*** 1.6.0-0ubuntu2 0
500 http://us.archive.ubuntu.com/ubuntu/ raring/main amd64 Packages
100 /var/lib/dpkg/status
1.2.3-0ubuntu2.3 0
500 http://bg.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
1.2.1-0ubuntu1 0
500 http://bg.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
然后，我运行了这个命令：apt-cache policy plymouth，得到了这个输出：
plymouth:
Installed: 0.8.8-0ubuntu6
Candidate: 0.8.8-0ubuntu6
Version table:
*** 0.8.8-0ubuntu6 0
500 http://us.archive.ubuntu.com/ubuntu/ raring/main amd64 Packages
100 /var/lib/dpkg/status
0.8.2-2ubuntu31.1 0
500 http://bg.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
0.8.2-2ubuntu30 0
500 http://bg.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
我该如何解决这个问题？谢谢，我的系统是 ubuntu13.04，64 位。
答案1
plymouth中的当前版本raring/main为0.8.8-0ubuntu6.2，而您缓存的 APT 列表中的版本为0.8.8-0ubuntu6。 这可能是由于镜像滞后导致的，这种情况下它会在一天内自行修复。
但是，强制 APT 获取最新的软件包列表也无妨。从系统中删除缓存的 APT 列表，然后运行以下命令apt-get update来刷新它们：
sudo rm -rf /var/lib/apt/lists/*
sudo apt-get update
在执行此操作之前，请注意您正在使用 12.04（precise）和 13.04（raring）档案。除非您有特殊原因，否则我建议删除 12.04 软件包源。此外，您似乎正在使用 PPA。禁用任何您不再需要的 PPA，因为这些也可能会扰乱依赖项管理。
答案2
跑步
sudo apt-get update
sudo apt-get dist-upgrade
应该升级保留的软件包。