The documentation of FreeRADIUS tells us to run radiusd -X to debug FreeRADIUS.
However, this daemon is not available in Debian:
$ apt-file search radiusd
freeradius: /etc/pam.d/radiusd
freeradius: /usr/share/doc/freeradius/deployment/supervise-radiusd.rst.gz
freeradius: /usr/share/doc/freeradius/examples/radiusd.cron.daily
freeradius: /usr/share/doc/freeradius/examples/radiusd.cron.monthly
freeradius: /usr/share/doc/freeradius/examples/radiusd.sh
freeradius: /usr/share/doc/freeradius/examples/radiusd2ldif.pl
freeradius: /usr/share/doc/freeradius/examples/rc.radiusd
freeradius: /usr/share/doc/freeradius/examples/rc.radiusd.in
freeradius-common: /usr/share/man/man5/radiusd.conf.5.gz
freeradius-config: /etc/freeradius/3.0/mods-config/python/radiusd.py
freeradius-config: /etc/freeradius/3.0/radiusd.conf
libfreeradius-dev: /usr/include/freeradius/radiusd.h
prelude-lml-rules: /etc/prelude-lml/ruleset/radiusd.rules
How do I get radiusd in Debian buster? Or how do I debug FreeRADIUS in another way?
It seems that in this package the binary was renamed to freeradius but the documentation was left unchanged.
The equivalent of radiusd is /usr/sbin/freeradius.