最近尝试使用crf++ 进行NER训练，在mac环境下，采用brew安装

brew install crf++
出现以下错误：
SSL routines:CONNECT_CR_SRVR_HELLO:wrong version number

解决方案：
在公司代理环境下，配置的https代理是没必要的，只需要 http代理即可，相关说明：

Uses proxy env variable httpproxy == 'https://proxy.in.tum.de:8080'
^^^^^
The https:// is wrong, it should be http://. The proxy itself should be accessed by HTTP and not HTTPS even though the target URL is HTTPS. The proxy will nevertheless properly handle HTTPS connection and keep the end-to-end encryption. See HTTP CONNECT method for details how this is done.

https://stackoverflow.com/questions/50840101/curl-35-error1408f10bssl-routinesssl3-get-recordwrong-version-number

But
mac实验，terminal中使用pip安装python程序，https proxy设置还是必要的，所以肯定是哪里设置有问题，对于https，其实可以这么设置：
https_proxy='http://proxy.in.tum.de:8080'