I can connect to a remote server with Tramp
C-x C-f /ssh:group@remotehost:
and get a plot output window (with ess R). But if I change user
C-x C-f /ssh:group@remote|su:user@remote:
there's no X11 forwarding anymore, i.e. not output window. Here's the error reported in R:
Error in .External2(C_X11, d$display, d$width, d$height, d$pointsize, : unable to start device X11cairo In addition: Warning message: In (function (display = "", width, height, pointsize, gamma, bg, : unable to open connection to X11 display ''
My ssh config file has
ForwardX11 yes and
ForwardX11trusted yes as described in Tramp manual. Am I missing something in my ssh config file or emacs init file, or is it on the server side?