Due to missing zwave devices in the database, I switched from the stable release (apt system) to the snapshot. After upgrade, system works OK, but I get NO LOGS at all. There are some lines in syslog, but the main log files and also log:display and log:tail are completely empty. I replaced the cfg file with the default but no change (which is what I expected, as log:get shows correct configuration).
The logging changed a while back in one of the snapshot releases, check out Log4j2 Sample Config to get an example on the new log method and syntax.