Seems to have started with the rollout of 1.30.0-wmf.9 to group1, is fairly noisy in error logs currently
#0 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/Checker/TargetRequiredClaimChecker.php(139): WikibaseQuality\ConstraintReport\ConstraintParameterRenderer->formatItemId(Wikibase\DataModel\Entity\PropertyId)
#1 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/DelegatingConstraintChecker.php(237): WikibaseQuality\ConstraintReport\ConstraintCheck\Checker\TargetRequiredClaimChecker->checkConstraint(Wikibase\DataModel\Statement\Statement, WikibaseQuality\ConstraintReport\Constraint, Wikibase\DataModel\Entity\Item)
#2 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/DelegatingConstraintChecker.php(216): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->getCheckResultFor(Wikibase\DataModel\Statement\Statement, WikibaseQuality\ConstraintReport\Constraint, Wikibase\DataModel\Entity\Item)
#3 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/DelegatingConstraintChecker.php(181): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkConstraintsForStatementOnEntity(array, Wikibase\DataModel\Entity\Item, Wikibase\DataModel\Statement\Statement)
#4 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/DelegatingConstraintChecker.php(147): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkStatement(Wikibase\DataModel\Entity\Item, Wikibase\DataModel\Statement\Statement, NULL)
#5 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/includes/ConstraintCheck/DelegatingConstraintChecker.php(104): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkEveryStatement(Wikibase\DataModel\Entity\Item, NULL)
#6 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/api/CheckConstraints.php(191): WikibaseQuality\ConstraintReport\ConstraintCheck\DelegatingConstraintChecker->checkAgainstConstraintsOnEntityId(Wikibase\DataModel\Entity\ItemId, NULL)
#7 /srv/mediawiki/php-1.30.0-wmf.9/extensions/Wikidata/extensions/Constraints/api/CheckConstraints.php(179): WikibaseQuality\ConstraintReport\Api\CheckConstraints->checkItems(array, NULL)
#8 /srv/mediawiki/php-1.30.0-wmf.9/includes/api/ApiMain.php(1583): WikibaseQuality\ConstraintReport\Api\CheckConstraints->execute()
#9 /srv/mediawiki/php-1.30.0-wmf.9/includes/api/ApiMain.php(546): ApiMain->executeAction()
#10 /srv/mediawiki/php-1.30.0-wmf.9/includes/api/ApiMain.php(517): ApiMain->executeActionWithErrorHandling()
#11 /srv/mediawiki/php-1.30.0-wmf.9/api.php(94): ApiMain->execute()
#12 /srv/mediawiki/w/api.php(3): include(string)
#13 {main}