我正在尝试使用 CentOS 6.6 和 c++ 创建一个 docker 容器：
Step 1/37 : FROM centos:6.6
---> 3d7ac13b921a
Step 2/37 : RUN yum -y update
---> Using cache
---> b41e216c79de
Step 3/37 : RUN yum -y install yum-plugin-ovl centos-release-scl
---> Using cache
---> a77e2870e01b
Step 4/37 : RUN yum -y install epel-release
---> Using cache
---> 95a1f9a75059
Step 5/37 : RUN yum -y install cmake3 devtoolset-4-gcc* hwloc-devel libmicrohttpd-devel openssl-devel make git
---> Using cache
---> 087a467c925c
Step 6/37 : RUN scl enable devtoolset-4 bash
---> Using cache
---> 5e98843aeb7f
Step 7/37 : RUN echo $PATH
---> Running in de0e7d3bd428
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
Removing intermediate container de0e7d3bd428
---> e7a900636a88
Step 8/37 : RUN c++ --version
---> Running in c51c9901049c
/bin/sh: c++: command not found
The command '/bin/sh -c c++ --version' returned a non-zero code: 127
但我明白
/bin/sh: c++: command not found
怎么了？