Centos7.5 安装centos-release-scl 报错：
No package centos-release-scl available.
已安装阿里云：
获取zabbix的下载源
cd /etc/yum.repos.d/
rpm -Uvh https://mirrors.aliyun.com/zabbix/zabbix/5.0/rhel/7/x86_64/zabbix-release-5.0-1.el7.noarch.rpm
更换zabbix.repo源，为阿里的：
sed -i 's#http://repo.zabbix.com#https://mirrors.aliyun.com/zabbix#' /etc/yum.repos.d/zabbix.repo
结果显示为：
baseurl=https://mirrors.aliyun.com/zabbix/zabbix/5.0/rhel/7/$basearch/
换了好几个源，都不行：
[root@localhost yum.repos.d]# yum -y install centos-release-scl
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* c7-media:
* epel: mirror.sjtu.edu.cn
No package centos-release-scl available.
Error: Nothing to do
我的版本是x86_64，符合
[root@localhost yum.repos.d]# uname -a
Linux localhost.localdomain 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
