No CMAKE_CXX_COMPILER could be found.

3查看错误日志

在第2步报错后，我们先去找Cmake的错误日志：一般在CmakeFiles文件夹下会有这个文件：CMakeError.log

打开看看：

Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler:  
Build flags: 
Id flags:  
The output was:
xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance
Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" failed.
Compiler:  
Build flags: 
Id flags:  
The output was:
xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance
Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" failed.
Compiler:  
Build flags: 
Id flags:  
The output was:
xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance

检查下命令行工具是否有安装：

xcode-select --install 
xcode-select: error: command line tools are already installed, use "Software Update" to install updates

百度一下：

https://www.cnblogs.com/huangfuql1314/p/8417597.html

终端输入：sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer

之后在去上边第一步操作构建的目录下执行构建命令：

cmake -B build **【自定义】*  -G Xcode

好了。。。。。。

切换xcode命令行版本
sudo xcode-select --switch /指定版本的xcode路径Xcode.app 
恢复默认的xcode命令行版本
当使用xcodebuild莫名其妙的出问题时，可以考虑使用此命令恢复
sudo xcode-select -r