https://travis-ci.org/wikimedia/mediawiki/jobs/415719055
PHP Notice: Trying to get property 'num_rows' of non-object in /home/travis/build/wikimedia/mediawiki/includes/libs/rdbms/database/DatabaseMysqli.php on line 233 PHP Stack trace: PHP 1. {main}() /home/travis/build/wikimedia/mediawiki/tests/phpunit/phpunit.php:0 PHP 2. require() /home/travis/build/wikimedia/mediawiki/tests/phpunit/phpunit.php:174 PHP 3. PHPUnitMaintClass->execute() /home/travis/build/wikimedia/mediawiki/maintenance/doMaintenance.php:94 PHP 4. PHPUnit\TextUI\Command::main() /home/travis/build/wikimedia/mediawiki/tests/phpunit/phpunit.php:135 PHP 5. PHPUnit\TextUI\Command->run() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/TextUI/Command.php:148 PHP 6. PHPUnit\TextUI\TestRunner->doRun() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/TextUI/Command.php:195 PHP 7. PHPUnit\Framework\TestSuite->run() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/TextUI/TestRunner.php:546 PHP 8. PHPUnit\Framework\TestSuite->run() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/Framework/TestSuite.php:755 PHP 9. PHPUnit\Framework\TestSuite->run() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/Framework/TestSuite.php:755 PHP 10. MediaWiki\Session\SessionInfoTest->run() /home/travis/build/wikimedia/mediawiki/vendor/phpunit/phpunit/src/Framework/TestSuite.php:755 PHP 11. MediaWiki\Session\SessionInfoTest->setUpSchema() /home/travis/build/wikimedia/mediawiki/tests/phpunit/MediaWikiTestCase.php:466 PHP 12. MediaWiki\Session\SessionInfoTest->undoSchemaOverrides() /home/travis/build/wikimedia/mediawiki/tests/phpunit/MediaWikiTestCase.php:1593 PHP 13. MediaWiki\Session\SessionInfoTest->recloneMockTables() /home/travis/build/wikimedia/mediawiki/tests/phpunit/MediaWikiTestCase.php:1579 PHP 14. CloneDatabase->cloneTableStructure() /home/travis/build/wikimedia/mediawiki/tests/phpunit/MediaWikiTestCase.php:1722 PHP 15. Wikimedia\Rdbms\DatabaseMysqli->duplicateTableStructure() /home/travis/build/wikimedia/mediawiki/includes/db/CloneDatabase.php:109 PHP 16. Wikimedia\Rdbms\DatabaseMysqli->query() /home/travis/build/wikimedia/mediawiki/includes/libs/rdbms/database/DatabaseMysqlBase.php:1454 PHP 17. Wikimedia\Rdbms\DatabaseMysqli->doProfiledQuery() /home/travis/build/wikimedia/mediawiki/includes/libs/rdbms/database/Database.php:1143 PHP 18. Wikimedia\Rdbms\DatabaseMysqli->numRows() /home/travis/build/wikimedia/mediawiki/includes/libs/rdbms/database/Database.php:1245 PHP 19. Wikimedia\Rdbms\DatabaseMysqli->mysqlNumRows() /home/travis/build/wikimedia/mediawiki/includes/libs/rdbms/database/DatabaseMysqlBase.php:370
I don't really understand how this notice is possible at all because this function is very clearly wrapped in suppressWarnings/restoreWarnings.