Help output generated by -h, --help flag is sent to stderr, probably should go to stdout instead

[atc0005]

While defining a new command for a Nagios XI system today I noticed an option to pick from an Available Plugins list. When I selected an official plugin from the list its help output was shown:

Selecting plugins from this project resulted in an empty text block being shown:

When testing via CLI:

$ /usr/local/nagios/libexec/check_users --help 2> /dev/null
check_users v2.3.3 (nagios-plugins 2.3.3)
Copyright (c) 1999 Ethan Galstad
Copyright (c) 2000-2014 Nagios Plugin Development Team
        <devel@nagios-plugins.org>

This plugin checks the number of users currently logged in on the local
system and generates an error if the number exceeds the thresholds specified.


Usage:
check_users -w <users> -c <users>

Options:
 -h, --help
    Print detailed help screen
 -V, --version
    Print version information
 --extra-opts=[section][@file]
    Read options from an ini file. See
    https://www.nagios-plugins.org/doc/extra-opts.html
    for usage and examples.
 -w, --warning=INTEGER
    Set WARNING status if more than INTEGER users are logged in
 -c, --critical=INTEGER
    Set CRITICAL status if more than INTEGER users are logged in

Send email to help@nagios-plugins.org if you have questions regarding use
of this software. To submit patches or suggest improvements, send email to
devel@nagios-plugins.org

$

Plugins from this project (and likely others that I maintain) send their output to stderr by default:

$ /usr/local/nagios/libexec/check_vmware_datastore --help 2> /dev/null
$

I'll need to check the official plugin guidelines to see if it indicates where help output should be sent. Based on the results shown above, I expect it will indicate stdout is the valid target.