risking a telling-off because it might be documented somewhere(!), I nevertheless cannot start the nymea-app on a Xubuntu 16.04 system. It fails with this error message:
triton:~$ sudo nymea-app No protocol specified qt.qpa.screen: QXcbConnection: Could not connect to display :0.0 Could not connect to any X display.
Which protocol do I have to specify, and is the lack of specifying the protocol the reason, the app cannot connect to the X-display?
Any hints much appreciated.