linuxlite ubuntu run synaptic on remote host

linuxlite ubuntu run synaptic on remote host

this fails

$ ssh remotehost
$ synaptic

with errors

Failed to connect to Mir: Failed to connect to server socket: 
No such file or directory
Unable to init server: Could not connect: Connection refused

this fails

$ ssh -X remotehost
$ su -
# synaptic

with errors

X11 connection rejected because of wrong authentication.
Failed to connect to Mir: Failed to connect to server socket: 
No such file or directory
Unable to init server: Could not connect: Connection refused

(synaptic:1659): Gtk-WARNING **: cannot open display: localhost:11.0

this works

$ ssh -X remotehost
$ sudo synaptic

BUT with warnings

** (synaptic:1403): WARNING **: 
Couldn't connect to accessibility bus: 
Failed to connect to socket /tmp/dbus-WJ1IDwyNzq: 
Connection refused