感觉是cmake没有找到你的c++编译器，是不是没有写入环境变量或者没写全？
手册上说也可以直接指定编译器的地址：

-DCMAKE_C_COMPILER=xxx equal to the name of the C99 Compiler you wish to use (or the environment variable CC)
-DCMAKE_CXX_COMPILER=xxx equal to the name of the C++98 compiler you wish to use (or the environment variable CXX)

把cmake做成cmake3的符号链接再试
还不行就按我的博文说的自己编译cmake3

cmake

But the scripts ask for cmake3

Soft link will solve your issue.