mac brew安装报错curl: (60) SSL certificate problem: certificate has expired

curl: (60) SSL certificate problem: certificate has expired
More details here: https://curl.haxx.se/docs/sslcerts.html

这个问题原因就是证书到期了，重新下载下证书就行了。

解决方案
打开浏览器下载pem文件，http://curl.haxx.se/ca/cacert.pem

然后备份一下系统原来的pem文件

cp /etc/ssl/cert.pem /etc/ssl/cert.bak.pem

之后将新下载的pem文件，拷贝到/etc/ssl/cert.pem

sudo mv ~/Downloads/cacert.pem /etc/ssl/cert.pem

再次下载就可以了