Thank you for the report! That escaped notice, the fix is to remove it from Makefile.in, since it is no longer used. The configure option is printed to inform the user in the help output and backwards compatibility, but there is no need for database directory or file. The commit removes the creation of the @dbdir@ directory, and also fixes dbfile references in the file edit and uninstall information, and in the nsd.conf man page that listed the database option in an example and database file under the FILES section of the man page.

Apart from briefly creating a spurious @dbdir@ directory, it does not misbehave during install for me. The fix removes that directory from being created. A test would likely not have caught it, since the mkdir command succeeds.

The additional commit fixes that for the xfrd.state and zone.list files, their directory is created at install time. This is more precise than creating the dbdir, it makes their directories also if they have been set, with configure options, to be stored at different locations.