想克隆备份的笔记库，失败。
测试连接github报错如下。

$ ssh -T git@github.com
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
The RSA host key for github.com has changed,
and the key for the corresponding IP address 140.82.121.4
is unknown. This could either mean that
DNS SPOOFING is happening or the IP address for the host
and its host key have changed at the same time.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:uNiVztksCsDhcc0u9e8BujQXVUpKZIDTMczCvj3tD2s.
Please contact your system administrator.
Add correct host key in xxx/.ssh/known_hosts to get rid of this message.
Offending RSA key in xxx/.ssh/known_hosts:8
RSA host key for github.com has changed and you have requested strict checking.
Host key verification failed.

在issue中搜到了相关问题，给出的解释是因为升级了ssh-key。
按照官方提示，在known_hosts文件中删去了github的rsa。

执行下面的命令，也可以手动删，之前自己配置的别的ip也要删。

ssh-keygen -R github.com

随后在known_hosts 文件中手动添加报错中提示的ip地址和github的公钥。（就是修改hosts文件配置的github解析ip），之后尝试ssh连接，一路yes即可成功连接github。