I followed all the instructions at https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/core/+/master/DEVELOPERS.md up to "run maintenance/update.php". At that point I got the following error:
Wikimedia\Rdbms\DBConnectionError from line 1418 of /Users/kaldari/Sites/mediawiki/includes/libs/rdbms/loadbalancer/LoadBalancer.php: Cannot access the database: Unknown error (localhost)
I have SQLite on my system (version 3.19.3). I did notice however that $wgDBserver, $wgDBuser, and $wgDBpassword are all set to empty string in my LocalSettings.php. Am I supposed to set that up manually? If so, it isn't mentioned in the instructions.