man page search path
When you add packages, sometimes their
man pages are not
properly added to the
$MANPATH used to find them using the
If $MANPATH is prefixed by a : then its value will be added to the default path. So the issue here is that when $MANPATH is null, no leading colon is used, which it why the man_db config is being ignored. So replacing
by a simpler
would be enough to solve the issue.