Swoole 编译出现 cmath 错误
mac 环境编译出现 fatal error:‘cmath’file not found，寻找半天问题，记录一下解决方法
临时设置环境变量，再次 make 即可
export C_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include export CPLUS_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1