github ssh: connect to host github.com port 22: Connection refused

$ git pull
ssh: connect to host github.com port 22: Connection refused
fatal: Could not read from remote repository.
​
Please make sure you have the correct access rights
and the repository exists.

原因分析：应该是 ssh 指纹验证过期了

解决方法

要在 SSH 配置文件中设置此设置，请编辑或新建文件 ~/.ssh/config，并添加以下部分：

Host github.com
Hostname ssh.github.com
Port 443
User git

然后 git push，会提醒确认 ssh 指纹验证信息，输入 yes后，即可成功 git push。