See e.g. https://gerrit.wikimedia.org/r/c/mediawiki/extensions/GrowthExperiments/+/719398 / https://integration.wikimedia.org/ci/job/mwext-php72-phan-docker/133771/console :
21:41:12 includes/Specials/SpecialClaimMentee.php:111 PhanUndeclaredTypeReturnType Return type of displayRestrictionError() is undeclared type \never 21:41:12 includes/Specials/SpecialEditGrowthConfig.php:168 PhanTypeMissingReturn Method \GrowthExperiments\Specials\SpecialEditGrowthConfig::displayRestrictionError is declared to return \never in phpdoc but has no return value 21:41:12 includes/Specials/SpecialEditGrowthConfig.php:168 PhanUndeclaredTypeReturnType Return type of displayRestrictionError() is undeclared type \never 21:41:12 includes/Specials/SpecialMentorDashboard.php:198 PhanUndeclaredTypeReturnType Return type of displayRestrictionError() is undeclared type \never
Caused by rMW44fd53fee326: Using @return never documentation on always-throw-function, maybe some extensions use a different version of phan?