As stated, the tutorial was written for 2.4.x, but the composer.json settings proffered would install 2.3.4, which has a different enough API that basic parts of the tutorial code would fail.
list_bugs.php needs to call to getters for protected vars. This was changed in the "getting-started" code repository, but not in the "getting-started" tutorial.
In the tutorial, the user is told to create a new file in the '/src' folder, and the 'entities' folder is never referenced. Updating the SQLite schema according to the tutorial fails with the 'No Metadata Classes to process.' message. Changing the folder to '/src' fixes this, ostensibly.