seen in a CI build running Selenium jobs (https://integration.wikimedia.org/ci/job/wmf-quibble-selenium-php74-docker/27049/console), passed on a recheck. Not sure if it's something that needs further investigation or an unavoidable edge case of how deferreds/jobs are run in our CI environment.
01:28:17 mw-dberror.log:Mon Mar 20 0:28:02 UTC 2023 ebfd34de8aa9 wikidb Error 1213 from MediaWiki\Storage\NameTableStore::store, Deadlock found when trying to get lock; try restarting transaction INSERT IGNORE INTO `change_tag_def` (ctd_name,ctd_user_defined,ctd_count) VALUES ('mobile web edit',0,0) localhost:/workspace/db/quibble-mysql-81ubnknv/socket 01:28:17 mw-dberror.log:#0 /workspace/src/includes/libs/rdbms/database/Database.php(1481): Wikimedia\Rdbms\Database->getQueryExceptionAndLog(string, integer, string, string) 01:28:17 mw-dberror.log:#1 /workspace/src/includes/libs/rdbms/database/Database.php(854): Wikimedia\Rdbms\Database->reportQueryError(string, integer, string, string, boolean) 01:28:17 mw-dberror.log:#2 /workspace/src/includes/libs/rdbms/database/Database.php(1755): Wikimedia\Rdbms\Database->query(string, string, integer) 01:28:17 mw-dberror.log:#3 /workspace/src/includes/libs/rdbms/database/DBConnRef.php(119): Wikimedia\Rdbms\Database->insert(string, array, string, array) 01:28:17 mw-dberror.log:#4 /workspace/src/includes/libs/rdbms/database/DBConnRef.php(400): Wikimedia\Rdbms\DBConnRef->__call(string, array) 01:28:17 mw-dberror.log:#5 /workspace/src/includes/Storage/NameTableStore.php(409): Wikimedia\Rdbms\DBConnRef->insert(string, array, string, array) 01:28:17 mw-dberror.log:#6 /workspace/src/includes/libs/rdbms/database/Database.php(2610): MediaWiki\Storage\NameTableStore->MediaWiki\Storage\{closure}(Wikimedia\Rdbms\DatabaseMysqli, string) 01:28:17 mw-dberror.log:#7 /workspace/src/includes/libs/rdbms/database/DBConnRef.php(119): Wikimedia\Rdbms\Database->doAtomicSection(string, Closure, string) 01:28:17 mw-dberror.log:#8 /workspace/src/includes/libs/rdbms/database/DBConnRef.php(680): Wikimedia\Rdbms\DBConnRef->__call(string, array) 01:28:17 mw-dberror.log:#9 /workspace/src/includes/Storage/NameTableStore.php(430): Wikimedia\Rdbms\DBConnRef->doAtomicSection(string, Closure, string) 01:28:17 mw-dberror.log:#10 /workspace/src/includes/Storage/NameTableStore.php(168): MediaWiki\Storage\NameTableStore->store(string) 01:28:17 mw-dberror.log:#11 /workspace/src/includes/changetags/ChangeTags.php(472): MediaWiki\Storage\NameTableStore->acquireId(string) 01:28:17 mw-dberror.log:#12 /workspace/src/includes/changetags/ChangeTags.php(335): ChangeTags::updateTags(array, array, integer, integer, string, NULL, RecentChange) 01:28:17 mw-dberror.log:#13 /workspace/src/includes/changes/RecentChange.php(488): ChangeTags::addTags(array, integer, integer, string, NULL, RecentChange) 01:28:17 mw-dberror.log:#14 /workspace/src/extensions/Wikibase/client/includes/Changes/InjectRCRecordsJob.php(265): RecentChange->save() 01:28:17 mw-dberror.log:#15 /workspace/src/includes/jobqueue/JobRunner.php(362): Wikibase\Client\Changes\InjectRCRecordsJob->run() 01:28:17 mw-dberror.log:#16 /workspace/src/includes/jobqueue/JobRunner.php(323): JobRunner->doExecuteJob(Wikibase\Client\Changes\InjectRCRecordsJob) 01:28:17 mw-dberror.log:#17 /workspace/src/includes/jobqueue/JobRunner.php(227): JobRunner->executeJob(Wikibase\Client\Changes\InjectRCRecordsJob) 01:28:17 mw-dberror.log:#18 /workspace/src/includes/MediaWiki.php(1197): JobRunner->run(array) 01:28:17 mw-dberror.log:#19 /workspace/src/includes/MediaWiki.php(647): MediaWiki->triggerSyncJobs(integer) 01:28:17 mw-dberror.log:#20 /workspace/src/includes/deferred/TransactionRoundDefiningUpdate.php(26): MediaWiki->{closure}() 01:28:17 mw-dberror.log:#21 /workspace/src/includes/deferred/DeferredUpdates.php(473): TransactionRoundDefiningUpdate->doUpdate() 01:28:17 mw-dberror.log:#22 /workspace/src/includes/deferred/DeferredUpdates.php(398): DeferredUpdates::attemptUpdate(TransactionRoundDefiningUpdate, Wikimedia\Rdbms\LBFactorySimple) 01:28:17 mw-dberror.log:#23 /workspace/src/includes/deferred/DeferredUpdates.php(213): DeferredUpdates::run(TransactionRoundDefiningUpdate, Wikimedia\Rdbms\LBFactorySimple, MediaWiki\Logger\LegacyLogger, BufferingStatsdDataFactory, MediaWiki\JobQueue\JobQueueGroupFactory, string) 01:28:17 mw-dberror.log:#24 /workspace/src/includes/deferred/DeferredUpdatesScope.php(267): DeferredUpdates::{closure}(TransactionRoundDefiningUpdate, integer) 01:28:17 mw-dberror.log:#25 /workspace/src/includes/deferred/DeferredUpdatesScope.php(196): DeferredUpdatesScope->processStageQueue(integer, integer, Closure) 01:28:17 mw-dberror.log:#26 /workspace/src/includes/deferred/DeferredUpdates.php(234): DeferredUpdatesScope->processUpdates(integer, Closure) 01:28:17 mw-dberror.log:#27 /workspace/src/includes/MediaWiki.php(1123): DeferredUpdates::doUpdates() 01:28:17 mw-dberror.log:#28 /workspace/src/includes/MediaWiki.php(854): MediaWiki->restInPeace() 01:28:17 mw-dberror.log:#29 /workspace/src/includes/MediaWiki.php(601): MediaWiki->doPostOutputShutdown() 01:28:17 mw-dberror.log:#30 /workspace/src/index.php(50): MediaWiki->run() 01:28:17 mw-dberror.log:#31 /workspace/src/index.php(46): wfIndexMain() 01:28:17 mw-dberror.log:#32 {main}