git "ssh-add ~/.ssh/id_rsa" Could not open a connection to your authentication agent问题解决

使用git，添加私钥时发生如下错误

ssh-add ~/.ssh/id_rsa

输出错误： Could not open a connection to your authentication agent

解决此问题的方法是执行下

eval `ssh-agent -s`

然后再次执行ssh-add ~/.ssh/id_rsa就可以顺利执行了