Package: openssh-client Version: 1:8.1p1-5The manual page says that -Y "does nothing in the default configuration". This is incorrect. The option, like -X, enables X11 forwarding:
$ DISPLAY=:42 ssh localhost 'echo DISPLAY=$DISPLAY' DISPLAY= $ DISPLAY=:42 ssh localhost -Y 'echo DISPLAY=$DISPLAY' Warning: No xauth data; using fake authentication data for X11 forwarding. DISPLAY=localhost:10.0 -- Jakub Wilk