As noted by @TobySpeight in theirhis answer to Polymorphic data models that save data to MySQL and restore data from MySQL the test code should also be reviewed. TheirHis suggestion for automating the build to include the test makes some sense as well, and I will look into it. Currently the test program does fail if tests fail, but the shell scripts don't check for the failure.
If you are running Ubuntu 24.04 with g++14 you can build it. If you have MariaDB or MySQL installed you should be able to run the program if you so desire. You will need to replace the username and password.