Today, I discovered that this happens with updateMenteeData.php at testwiki:
[urbanecm@mwmaint1002 /srv/mediawiki/php]$ mwscript extensions/GrowthExperiments/maintenance/updateMenteeData.php --wiki=testwiki
InvalidArgumentException from line 2690 of /srv/mediawiki/php-1.37.0-wmf.23/includes/libs/rdbms/database/Database.php: Wikimedia\Rdbms\Database::makeList: empty input for field actor_rev_user.actor_user
#0 /srv/mediawiki/php-1.37.0-wmf.23/includes/libs/rdbms/database/Database.php(2071): Wikimedia\Rdbms\Database->makeList(Array, 1)
#1 /srv/mediawiki/php-1.37.0-wmf.23/includes/libs/rdbms/database/Database.php(2010): Wikimedia\Rdbms\Database->selectSQLText(Array, Array, Array, 'GrowthExperimen...', Array, Array)
#2 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/includes/MentorDashboard/MenteeOverview/UncachedMenteeOverviewDataProvider.php(159): Wikimedia\Rdbms\Database->select(Array, Array, Array, 'GrowthExperimen...', Array, Array)
#3 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/includes/MentorDashboard/MenteeOverview/UncachedMenteeOverviewDataProvider.php(175): GrowthExperiments\MentorDashboard\MenteeOverview\UncachedMenteeOverviewDataProvider->getLastEditTimestampForUsers(Array)
#4 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/includes/MentorDashboard/MenteeOverview/UncachedMenteeOverviewDataProvider.php(136): GrowthExperiments\MentorDashboard\MenteeOverview\UncachedMenteeOverviewDataProvider->filterMenteesByLastEdit(Array)
#5 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/includes/MentorDashboard/MenteeOverview/UncachedMenteeOverviewDataProvider.php(197): GrowthExperiments\MentorDashboard\MenteeOverview\UncachedMenteeOverviewDataProvider->getFilteredMenteesForMentor(Object(User))
#6 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/maintenance/updateMenteeData.php(106): GrowthExperiments\MentorDashboard\MenteeOverview\UncachedMenteeOverviewDataProvider->getFormattedDataForMentor(Object(User))
#7 /srv/mediawiki/php-1.37.0-wmf.23/maintenance/doMaintenance.php(108): GrowthExperiments\Maintenance\UpdateMenteeData->execute()
#8 /srv/mediawiki/php-1.37.0-wmf.23/extensions/GrowthExperiments/maintenance/updateMenteeData.php(200): require_once('/srv/mediawiki/...')
#9 /srv/mediawiki/multiversion/MWScript.php(116): require_once('/srv/mediawiki/...')
#10 {main}
[urbanecm@mwmaint1002 /srv/mediawiki/php]$I'm not sure why. Might be related to some user not having any mentees?