Error: "binary operator expected" when attempting to stop ndsd

When attempting to stop ndsd using the /etc/init.d/ndsd script, the console prints a failure message like this:

/etc/init.d/ndsd: line 244: [: /var/nds/data: binary operator expected

The script does seem to successfully stop the ndsd process, but it does not clean up the ndsd pid file which results in an error that ndsd was not shut down cleanly upon the next start.  You may also receive further errors in the post_ndsd_start script.

This issue is caused by duplicated lines in the nds.conf file.  For instance, there may be two n4u.server.vardir directives.  It does not make a difference if they are the same or different values.

To resolve the issue, make sure that each directive in the nds.conf file appears only once.

This has been fixed in the latest versions of 8.7.3 and 8.8.