运行 11.04 后，由于某些需求，我降级到了 php5.2。我不记得怎么做了。我现在想恢复到 5.3。我尝试使用 apt-get upgrade，但收到以下消息：
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
krb5-multidev : Depends: libkrb5-3 (= 1.8.3+dfsg-5ubuntu2.2) but 1.9.1+dfsg-1ubuntu2.2 is installed
libgssapi-krb5-2 : Depends: libkrb5-3 (= 1.8.3+dfsg-5ubuntu2.2) but 1.9.1+dfsg-1ubuntu2.2 is installed
libkrb5-3 : Depends: libk5crypto3 (>= 1.9+dfsg~beta1) but 1.8.3+dfsg-5ubuntu2.2 is installed
Depends: libkrb5support0 (= 1.9.1+dfsg-1ubuntu2.2) but 1.8.3+dfsg-5ubuntu2.2 is installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
E: Unable to correct dependencies
我没能找到任何修复的线索。
如果我需要提供更多信息，请告诉我。
编辑：添加 /etc/apt/preferences.d 列表
:/etc/apt/preferences.d$ ll
total 12
drwxr-xr-x 2 root root 4096 2011-10-15 11:14 ./
drwxr-xr-x 6 root root 4096 2012-02-07 23:39 ../
-rw-r--r-- 1 root root 738 2011-10-15 11:14 php
/etc/apt 列表
/etc/apt$ ll
total 76
drwxr-xr-x 6 root root 4096 2012-02-07 23:39 ./
drwxr-xr-x 161 root root 12288 2012-02-09 09:36 ../
drwxr-xr-x 2 root root 4096 2011-11-29 10:47 apt.conf.d/
drwxr-xr-x 2 root root 4096 2011-10-15 11:14 preferences.d/
-rw------- 1 root root 0 2011-04-25 18:52 secring.gpg
-rw-r--r-- 1 root root 3277 2012-01-02 20:14 sources.list
drwxr-xr-x 2 root root 4096 2012-01-03 09:44 sources.list.d/
-rw-r--r-- 1 root root 3277 2012-01-02 20:14 sources.list.save
-rw------- 1 root root 1200 2012-01-02 20:05 trustdb.gpg
-rw-r--r-- 1 root root 13937 2012-01-02 20:05 trusted.gpg
-rw-r--r-- 1 root root 13937 2012-01-02 20:05 trusted.gpg~
drwxr-xr-x 2 root root 4096 2011-04-07 07:13 trusted.gpg.d/
答案1
this may be caused by held packages
是的，可能就是这样。aptitude是一个非常方便的交互式命令行工具，用于安装包，还用于调查奇怪的事情发生。
尝试一下，它可能会告诉你哪里出了问题（或者当你尝试升级 php 时出现了什么问题）。