There is an error when using git to pull the GitHub code base

LibreSSL SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443

The solution is as follows:
1 Cancel global proxy first:

git config --global --unset https.proxy
git config --global --unset http.proxy

2. Configure global agent:

git config --global http.https://github.com.proxy socks5://127.0.0.1:1080 
git config --global https.https://github.com.proxy socks5://127.0.0.1:1080

Note that 1080 is changed to the port number of its own proxy service