When forked to the background, hostapd is capable to use syslog for logging making it quite hard to troubleshoot issues on the Wifi phy and mac layers. However, I have found this feature to be disabled in all VyOS versions by this hostapd.conf setting: `logger_syslog_level=0`
Manually enabling this (for example set `logger_syslog_level=4`) and then restarting hostapd in forked mode still does not make it log to syslog.
I tested this on VyOS 1.1.8 and 1.2.x.
Telated to: T452