比如
Transaction Check Error:
package apr-1.3.12-1.jason.1.x86_64 (which is newer than apr-1.2.7-11.el5_6.5.cloudlinux.2.i386) is already installed
先尝试使用 yum downgrade 把 apr 降级（基本不可能），然后用 rpm -e --nodeps apr 强制卸载
参考资料：
http://serverfault.com/questions/325595/yum-update-dependency-error-already-installed