I have several machines on my LAN and my main workstation called lagrangian. Machines can ping lagrangian. All machines can have
DISPLAY=lagrangian:0
set. I run VcXsrv on lagrangian and hence can run any XWindow applications of other machines, having windows displayed on lagrangian.
Except one. It says
Error: Can't open display:
What can be a reason?
The error message line ends with the value of the display it is trying to connect to. Since there is nothing on the line you probably have failed to set the environment variable on that machine for some reason. Try printenv DISPLAY to verify. If it was correct it would print lagrangian:0, but I suspect it won't.
printenv DISPLAY isn't as portable as echo $DISPLAY. Just a note, in case he's not got your exact environment.
echo $DISPLAY will show also shell variables that are not exported to the environment. If someone sets the variable without doing export, (s)he might be fooled if doing it with echo.
Try doing xhost +.
In my case when I tried to run a grphaic application (ddd, a display debugger) with sudo, it gave me can't open display :2. The DISPLAY variable was set to :2 (I was using vnc). Without sudo, ddd window comes up but it couldn't attach to the program I wanted to debug. So I tried xhost + and the ddd window came up ok also attaching to the program.
