Hello,

As of today, MediaWiki development settings now ask MySQL/MariaDB to report error for a wide range of issues that just emitted a warning previously. That is done in includes/DevelopmentSettings.php by setting:

$wgSQLMode = 'TRADITIONAL';

As such, you might see database errors occurring on CI runs. We definitely need them to be tracked and fixed to later enable a stricter mode on the Wikimedia cluster.

Why does it matter?

In short, without the stricter mode, the server might just truncate some rows, fallback to some default or just truncate the value!

We had a RFC written back in 2015 about the subject which gives the rationale and examples: https://phabricator.wikimedia.org/T112637

Thus if you encounter an error, please do fill a sub task for T108255.

Ref: mediawiki/core change https://gerrit.wikimedia.org/r/429386/ For CI/dev: https://phabricator.wikimedia.org/T119371 For production: https://phabricator.wikimedia.org/T108255