[root@localhost folly.lib]# yum search devtoolset
已加载插件：fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* epel: mirrors.tuna.tsinghua.edu.cn
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
=============================================== N/S matched: devtoolset ===============================================
devtoolset-7-runtime.x86_64 : Package that handles devtoolset-7 Software Collection.
devtoolset-8-runtime.x86_64 : Package that handles devtoolset-8 Software Collection.
devtoolset-7-binutils.x86_64 : A GNU collection of binary utilities
devtoolset-7-gcc.x86_64 : GCC version 7
devtoolset-7-gcc-c++.x86_64 : C++ support for GCC version 7
devtoolset-7-libstdc++-devel.x86_64 : Header files and libraries for C++ development
devtoolset-8-binutils.x86_64 : A GNU collection of binary utilities
devtoolset-8-gcc.x86_64 : GCC version 8
devtoolset-8-gcc-c++.x86_64 : C++ support for GCC version 8
devtoolset-8-libstdc++-devel.x86_64 : Header files and libraries for C++ development
名称和简介匹配 only，使用“search all”试试。
[root@localhost folly.lib]#
yum install devtoolset-7-gcc.x86_64 devtoolset-7-gcc-c++.x86_64
在使用gcc7之前,输入:source /opt/rh/devtoolset-7/enable,从4.8切换7.3