In a just installed and updated system, I found that running named using the -g switch directly from the command line worked, but from the sv script, was failing with defunct.
I changed the -f switch -g in /etc/sv/named/run
mkdir -p /var/run/named || exit 1
chown named:named /var/run/named || exit 1
exec named -u named -g -c /etc/named/named.conf
and sv start named worked.