ottengo questa risposta:

carlo@kubuntu:~$ sudo kate
Password:
Error: "/var/tmp/kdecache-carlo" is owned by uid 1000 instead of uid 0.
Creating link /root/.kde/cache-kubuntu.
Created link from "/root/.kde/cache-kubuntu" to "/var/tmp/kdecache-root"
kate: ERROR: Communication problem with kate, it probably crashed.