PHPUnit 10 marks empty data provider as invalid with the text "Empty data set provided by data provider" and count this as errors.
Some of the provider of the abstract HTMLFormFieldTestCase are designed to return empty array in case there is nothing to test.
But that does not work under PHPUnit 10.
Example from WikimediaEvents
1) WikimediaEvents\Tests\Integration\CreateAccount\HTMLNoScriptHiddenFieldTest::testGetCodex The data provider specified for WikimediaEvents\Tests\Integration\CreateAccount\HTMLNoScriptHiddenFieldTest::testGetCodex is invalid Empty data set provided by data provider WikimediaEvents\tests\phpunit\integration\CreateAccount\HTMLNoScriptHiddenFieldTest.php:97