the guy from the support team who called my on tuesday as reaction to my mail to email@example.com on sunday evening requested my to post that Bug in the installation script also here in the forum. To make it easy, this was my mail:
Hi all, I found o other place to place this Bug report, so I’m trying this way and hope it comes to the right people: I found a little bug in the installation script from install.opsview.com. I assume it is related to mysqladmin. I’ve choosen a random password to fill in at the point where the scripts ask me for the database root password. That password had some special characters includes. A $ at the beginning and a % at the end. With this password the script is not able to login to MySQL/MariaDB to install the Opsview Database. During analysis of that behaviour I found out, that also mysqladmin has that problem. So I think the behaviour of your installation scrip is linked directly to mysqladmin and the way the password is piped to mysqladmin has changed.
The guy told me, that I'm not the first one who is contacting them having that issue and that there is a general problem with special characters in the MySQL root password and not with that two characters.