Clone https://github.com/moodlehq/moodle-docker and configure its environment: export MOODLE_DOCKER_WWWROOT=</path/to/moodle> export MOODLE_DOCKER_DB=pgsql (to ensure that we're using the default setting) Ensure that in base.yml you read: image: postgres:9.6.7 Start the docker env and setup the unit tests environment, within the folder where the repo above has been cloned: bin/moodle-docker-compose up -d && bin/moodle-docker-wait-for-db && bin/moodle-docker-compose exec webserver php admin/tool/phpunit/cli/init.php (Regression) Run the DDL tests: bin/moodle-docker-compose exec webserver php vendor/bin/phpunit --verbose core_ddl_testcase lib/ddl/tests/ddl_test.php Stop the docker env: bin/moodle-docker-compose down Edit the base.yml file to update the postgresql image version: image: postgres:9.6. 8 Rerun the setup of the docker env including the setup of the unit tests and then run the broken unit tests (DDL)