Изменить время ожидания отображения GDM

Из прекрасного руководства для git (1) мы находим

   GIT_SSH, GIT_SSH_COMMAND
       If either of these environment variables is set then git fetch and
       git push will use the specified command instead of ssh when they
       need to connect to a remote system. The command will be given
       exactly two or four arguments: the username@host (or just host)
       from the URL and the shell command to execute on that remote
       system, optionally preceded by -p (literally) and the port from the
       URL when it specifies something other than the default SSH port.

       $GIT_SSH_COMMAND takes precedence over $GIT_SSH, and is interpreted
       by the shell, which allows additional arguments to be included.
       $GIT_SSH on the other hand must be just the path to a program
       (which can be a wrapper shell script, if additional arguments are
       needed).

Поэтому простейшая интерпретация через оболочку - это

GIT_SSH_COMMAND="ssh -f" git push ...

или полная оболочка через GIT_SSH .