GIT_SSH
           If this environment variable is set then git fetch and git push will use this command instead of ssh when
           they need to connect to a remote system. The $GIT_SSH command will be given exactly two arguments: the
           username@host (or just host) from the URL and the shell command to execute on that remote system.

           To pass options to the program that you want to list in GIT_SSH you will need to wrap the program and
           options into a shell script, then set GIT_SSH to refer to the shell script.

           Usually it is easier to configure any desired options through your personal .ssh/config file. Please
           consult your ssh documentation for further details.