How do I debug Tradfri on Openhab ?

open the openhab-cli:

root@rpi6:/home/pi# openhab-cli console

Logging in as openhab

                          __  _____    ____
  ____  ____  ___  ____  / / / /   |  / __ )
 / __ \/ __ \/ _ \/ __ \/ /_/ / /| | / __  |
/ /_/ / /_/ /  __/ / / / __  / ___ |/ /_/ /
\____/ .___/\___/_/ /_/_/ /_/_/  |_/_____/
    /_/                        2.5.0.M4
                               Milestone Build

Hit '<tab>' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit '<ctrl-d>' or type 'system:shutdown' or 'logout' to shutdown openHAB.

Find the packacke-namespace of the tradfri bundle:

openhab> bundle:list -s|grep trad
226 │ Active │  80 │ 2.5.0.M4              │ org.openhab.binding.tradfri

get the current debug-level:

openhab> log:get org.openhab.binding.tradfri
INFO

change the debug-level if needed:

openhab> log:set ERROR org.openhab.binding.tradfri
openhab> log:set DEBUG org.openhab.binding.tradfri
openhab> log:set INFO org.openhab.binding.tradfri