PHPUnit 10 reports a risky test with the reason "Test code or tested code printed unexpected output".
The config in phpunit.xml.template has failOnRisky="true", so this risky test, makes PHPUnit fail.
There was 1 risky test: 1) PerformanceBudgetTest::testTotalModulesSize Test code or tested code printed unexpected output: Some tests raised warnings: Total size of styles modules is 19.2kB ( 160.7 kB uncompressed). If you are adding code on page load, please reduce styles that you are loading on page load. Read https://www.mediawiki.org/wiki/Performance_budgeting for more context on this number. Total size of scripts modules is 110.6kB ( 412.6 kB uncompressed). If you are adding code on page load, please reduce scripts that you are loading on page load. Read https://www.mediawiki.org/wiki/Performance_budgeting for more context on this number.
Related: 2f6871306cccb7101c0f35071b00c3cb24ed2ef6 / T391835: PerformanceBudgetTest should not print text in the middle of all MediaWiki PHPUnit runs