PHPUnit's manual recommends the PHPUnit phar as the easiest way to obtain PHPUnit and its dependencies. Unfortunately, when PHPUnit is loaded via a phar file, there appears to be no way to use it to run MediaWiki's test suites. If you try to execute the tests by invoking the phar file, MediaWiki's environment is not set up. If you attempt to use MediaWiki's own tests/phpunit/phpunit.php, you find that there is no way to get MediaWiki to resolve its includes / requires using the phar file: --with-phpunitdir could presumably add the phar file to include_path (which is supported by PHP, AFAIK), but it currently chokes on anything that isn't an actual directory.
Version: 1.23.0
Severity: critical