nagios core install | nagios core | nagios plugins | nagios ssh
    apt install autoconf automake gcc libc6 libmcrypt-dev make libssl-dev wget bc gawk dc build-essential snmp libnet-snmp-perl gettext
    # ldap + mysql + dns + samba + fping
    apt install libldap2-dev libmariadb-dev libmariadb-dev-compat dnsutils smbclient fping
(should be fine with a full system)
grab the latest plugins
    ver=2.4.5
    #wget https://github.com/nagios-plugins/nagios-plugins/archive/release-2.4.0.tar.gz
    wget https://github.com/nagios-plugins/nagios-plugins/archive/refs/tags/release-$ver.tar.gz
tar xzf release-$ver.tar.gz
    cd nagios-plugins-release-$ver/
    ./tools/setup
    ./configure --sysconfdir=/etc --localstatedir=/var/nagios
    grep WARNING config.log
    echo $MAKEFLAGS
    make
    make install
https://support.nagios.com/kb/article.php?id=569#Debian
https://nagios-plugins.org/nagios-plugins-1-5-released/