ubuntu20.04 cmake编译出错：No CMAKE_CXX_COMPILER could be found.

-- The cxx compiler identification is unknown
CMake Error at CMakeLists.txt:3 (project) :
    No CMAKE_CXX_COMPILER could be found.
Tell CNake where to find the compiler by setting either the environment
variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
to the compiler, or to the compiler name if it is in the PATH.

-- Configuring incomplete,errors occurred !

大概率是因为c++编译环境不全，即使安装过gcc/g++也会出现，所以提供了一键安装命令，所有依赖都会安装上：

sudo apt install -y build-essential