yum “There are unfinished transactions remaining”

今天在服务器用yum安装东西的时候，总是报:

There are unfinished transactions remaining. You might consider running yum-complete-transaction, or "yum-complete-transaction --cleanup-only" and "yum history redo last", first to finish them. If those don't work you'll have to try removing/installing packages by hand (maybe package-cleanup can help).
The program yum-complete-transaction is found in the yum-utils package.

意思是：有未完成的yum事务，建议先运行yum-complete-transaction命令清除，经查找，原来有强制结yum过；
安装 yum-complete-transaction（这是一个能发现未完成或被中断的yum事务的程序）

yum -y install yum-utils

运行 yum-complete-transaction 清理未完成事务

yum-complete-transaction --cleanup-only