su error

> pkexec kate
THIS IS POTENTIALLY INSECURE!
To edit files as root please use:
SUDO_EDITOR=kwrite sudoedit <file>
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
No protocol specified
No protocol specified
qt.qpa.screen: QXcbConnection: Could not connect to display :0
Could not connect to any X display.