Cannot load the container with xephyr (xephir doesn't even start)

[brunoais]

me@myPC:/path/to/repos/xfce-test$ sudo -u dockerU ./xfce-test start
[sudo] password for me: 
You are working with the container: latest
No protocol specified

Xephyr cannot open host display. Is DISPLAY set?
xfce-test-1

I'm running ubuntu. I don't get what is wrong. Reading the xfce-test isn't helping either

[schuellerf]

This is not really related to Xephir. Your X11 setup is somehow wrong that the user "dockerU" can't access the DISPLAY of the user "me".
As a workaround you can try enabling all of your local users access to your display
xhost +LOCAL:
and then call your sudo … command again

[brunoais]

OK!.... That was the issue. Thank you.