X11 display forwarding for root

• The problem:

  [wilson@local-host]$ ssh -Y -A -t -C -o CompressionLevel=9 wilson@remote-host
  [wilson@remote-host]$ sudo su
  [root@remote-host]$ xclock
  X11 connection rejected because of wrong authentication.
  Error: cannot open display: localhost:10.0
  

• The solution:

  [wilson@local-host]$ ssh -Y -A -t -C -o CompressionLevel=9 wilson@remote-host
  [wilson@remote-host]$ sudo su
  [root@remote-host]$ su - wilson -c 'xauth list' | grep $(echo $DISPLAY | cut -d ':' -f 2 | cut -d '.' -f 1 | sed -e s/^/:/) | xargs -n 3 xauth add
  [root@remote-host]$ xclock
  

See also

• Make X11 programs work in an ssh sudo session