A very annoying upgrade issue I encountered when using the configuration of a < 9.4 site for a 9.4 website:
[error] Drupal\Core\Config\ConfigImporterException: There were errors validating the config synchronization. Unable to uninstall the MySQL module because: The module 'MySQL' is providing the database driver 'mysql'.. in Drupal\Core\Config\ConfigImporter->validate() (line 756 of /app/web/core/lib/Drupal/Core/Config/ConfigImporter.php).
Add the following line to the module key in your core.extension.yml:
And so the solution is to roll back the code to Drupal 9.3, do your installation from configuration, and then run the database updates, export configuration, and commit the result.
git checkout <commit-hash-of-earlier-composer-lock> composer install drush -y site:install drutopia --existing-config git checkout main composer install drush -y updb drush -y cex git status # Review what is here; git add -p can also help git add config/ git commit -m "Apply configuration updates from Drupal 9.4 upgrade"
The system update
enable_provider_database_driver is the
post-update hook that is doing the work here to "Enable the modules that are providing the listed database drivers." Pretty cool feature and a strong reminder to always, always run database updates and commit any configuration changes immediately after any code updates!