解决Another app is currently holding the yum lock; waiting for it to exit...

[root@bogon ~]# yum install gcc-c++ Loaded plugins: fastestmirror, refresh-packagekit, securityExisting lock /var/run/yum.pid: another copy is running as pid 2395.Another app is currently holding the yum lock; waiting for it to exit...  The other application is: PackageKit    Memory :  20 M RSS ( 35 MB VSZ)    Started: Thu Jul 20 11:25:58 2017 - 8:01:01 ago    State  : Sleeping, pid: 2395

这里的意思是yum被占用所以需要把这个进程干掉！！！
解决办法：
第一种办法：

 kill -s 9 2395

第二种办法：
要是第一种没效果就用下面语句：

rm -f /var/run/yum.pid

然后使用ps命令

ps aux|grep yum

查看占用yum的进程是否被干掉
然后安心的使用yum命令吧。。。我这里安装的是gcc

 yum install gcc-c++ 

---