when running phpunit tests locally:
Wikibase\Lib\Tests\Modules\SitesModuleTest::testGetScript
MWException: Message::inLanguage must be passed a String or Language object; NULL given
/var/www/wiki/w/includes/Message.php:677
/var/www/wiki/w/extensions/Wikidata/extensions/Wikibase/lib/includes/Modules/SitesModuleWorker.php:190
/var/www/wiki/w/extensions/Wikidata/extensions/Wikibase/lib/includes/Modules/SitesModuleWorker.php:147
/var/www/wiki/w/extensions/Wikidata/extensions/Wikibase/lib/includes/Modules/SitesModuleWorker.php:125
/var/www/wiki/w/extensions/Wikidata/extensions/Wikibase/lib/includes/Modules/SitesModule.php:45
/var/www/wiki/w/extensions/Wikidata/extensions/Wikibase/lib/tests/phpunit/Modules/SitesModuleTest.php:31