I have set $wgCommentTableSchemaMigrationStage = MIGRATION_WRITE_NEW in my LocalSettings.php.
When running php tests\parser\parserTests.php --quiet it fails with some database errors, because the new comment table and some other tables are not cloned on the parser test run.
ParserTestRunner::listTables needs some table names. I have no idea what is happen when the list contains non existing tables for the old developer installation.