MAC安装M2Crypto报command 'cc' failed with exit status 1

出错分析主要是因为由于OSX升级之后 /usr/include 没有了，使用命令修改swig寻址路径：

sudo env LDFLAGS="-L$(brew --prefix openssl)/lib" \

CFLAGS="-I$(brew --prefix openssl)/include" \

SWIG_FEATURES="-cpperraswarn -includeall -I$(brew --prefix openssl)/include" \

pip install m2crypto