If you want to test the upcoming XOOPS version 2.5.10 on PHP 7.3 RC5 and MySQL 8.0.13 using Docker, the files are here:
https://github.com/geekwright/xoops_mysql8

Make sure you read the Readme.md file

Richard (aka Geekwright) is testing and is fixing potential issues. So far he has found only a few issues running under MySQL 8.0. The expanded reserved word list is one. There are also issues with using PHP with the new default authentication plugin in MySQL 8.0, caching_sha2_password.
Docker version above sets default-authentication-plugin=mysql_native_password.

The 'rank' column in users table is a reserve word, and needs to be `quoted`

Richard changed criteria class to use quotes on criteria column names to prevent reserved word issues.

I have installed the Docker version and it worked perfectly. I'll need to test some modules...

Background on problems.
---------------------------------
https://dev.mysql.com/doc/refman/8.0/en/keywords.html

https://mysqlserverteam.com/upgrading-to-mysql-8-0-default-authentication-plugin-considerations/