当我做sudo yum update时，我得到以下错误。 在得到这个错误之前我做的唯一事情就是将Python 2.7安装在Python 2.4以外的目录中。 服务器上的默认Python仍然是2.4：
Error: Missing Dependency: php-common = 5.2.4-el5.centos is needed by package php-mhash Error: Missing Dependency: libnss3.so(NSS_3.12) is needed by package libcurl Error: Missing Dependency: libnssutil3.so is needed by package libcurl
这是整个命令：
sudo yum update Loading "installonlyn" plugin Setting up Update Process Setting up repositories rightscale 100% |=========================| 951 B 00:00 Reading repository metadata in from local files Resolving Dependencies --> Populating transaction set with selected packages. Please wait. ---> Package php-xml.i386 0:5.3.2-1 set to be updated ---> Package git.i386 0:1.6.4.2-1 set to be updated ---> Package perl-Git.i386 0:1.6.4.2-1 set to be updated ---> Package php-mysql.i386 0:5.3.2-1 set to be updated ---> Package mysql.i386 0:5.0.89-1 set to be updated ---> Package mysql-devel.i386 0:5.0.89-1 set to be updated ---> Package php-pdo.i386 0:5.3.2-1 set to be updated ---> Package GeoIP.i386 0:1.4.7-0.1.20090931cvs set to be updated ---> Package autoconf.noarch 0:2.63-2 set to be updated ---> Package sqlite.i386 0:3.6.17-1 set to be updated ---> Package php-mcrypt.i386 0:5.3.2-1 set to be updated ---> Package php-pear.noarch 1:1.9.0-1 set to be updated ---> Package GeoIP-devel.i386 0:1.4.7-0.1.20090931cvs set to be updated ---> Package php-pecl-memcache.i386 0:3.0.4-3 set to be updated ---> Package php-devel.i386 0:5.3.2-1 set to be updated ---> Package mysql-server.i386 0:5.0.89-1 set to be updated ---> Package php-cli.i386 0:5.3.2-1 set to be updated ---> Package m4.i386 0:1.4.12-2 set to be updated ---> Package php-gd.i386 0:5.3.2-1 set to be updated ---> Package php.i386 0:5.3.2-1 set to be updated ---> Package php-common.i386 0:5.3.2-1 set to be updated --> Running transaction check --> Processing Dependency: libedit.so.0 for package: php-cli --> Processing Dependency: libltdl.so.3 for package: php-mcrypt --> Processing Dependency: php-common = 5.2.4-el5.centos for package: php-mhash --> Processing Dependency: libt1.so.5 for package: php-gd --> Processing Dependency: libcurl.so.4 for package: php-common --> Restarting Dependency Resolution with new changes. --> Populating transaction set with selected packages. Please wait. ---> Package t1lib.i386 0:5.1.1-7.el5 set to be updated ---> Package libedit.i386 0:2.11-1.20080712cvs.el5 set to be updated ---> Package libcurl.i386 0:7.19.6-5 set to be updated ---> Package libtool-ltdl.i386 0:1.5.22-6.1 set to be updated --> Running transaction check --> Processing Dependency: libnss3.so(NSS_3.12) for package: libcurl --> Processing Dependency: libssh2.so.1 for package: libcurl --> Processing Dependency: php-common = 5.2.4-el5.centos for package: php-mhash --> Processing Dependency: libnssutil3.so for package: libcurl --> Restarting Dependency Resolution with new changes. --> Populating transaction set with selected packages. Please wait. ---> Package libssh2.i386 0:0.18-9.el5 set to be updated --> Running transaction check --> Processing Dependency: libnss3.so(NSS_3.12) for package: libcurl --> Processing Dependency: php-common = 5.2.4-el5.centos for package: php-mhash --> Processing Dependency: libnssutil3.so for package: libcurl --> Finished Dependency Resolution Error: Missing Dependency: php-common = 5.2.4-el5.centos is needed by package php-mhash Error: Missing Dependency: libnss3.so(NSS_3.12) is needed by package libcurl Error: Missing Dependency: libnssutil3.so is needed by package libcurl
问题来自“rightscale”存储库。 你可能从这个版本库安装了php-5.2和php-mhash，现在他们想要升级你的系统到php-5.3，但是并没有升级所有的模块。
我build议你运行：
yum --disablerepo rightscale update
看看会发生什么。 为了更新你的PHP软件包，你应该联系rightscale并报告他们的问题，或者只使用Centos / Redhat / ScientificLinux中的软件包（无论你的基本发行版，php-5.1和php53是否可用），或者其他第三方如“ius”，以获得额外的软件包，如php-5.2