The unauthenticated git protocol on port 9418 is no longer supported

fatal: 远程错误：The unauthenticated git protocol on port 9418 is no longer supported.
Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/ for more information.

问题解决：

git config --global url."https://github.com/".insteadOf git://github.com/

参考文献

https://github.com/actions/checkout/issues/14#issuecomment-523916396

Improving Git protocol security on GitHub