There were 6 errors:

1) MassAction\Test\MassActionExtTest::testGetDefaultInstanceReturnsSameInstance
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94

2) MassAction\Test\MassActionExtTest::testConstructionHandlesConfigCorrectly
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94

3) MassAction\Test\MassActionExtTest::testGetDebReturnesDb
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94

4) MassAction\Test\MassActionExtTest::testGetListerForTargetTypeCanReturnNull
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94

5) MassAction\Test\MassActionExtTest::testMediaWikiTestCaseParentSetupCalled
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94

6) MassAction\Test\MassActionExtTest::testValidCovers
Use of MediaWikiTestCase::stashMwGlobals was deprecated in MediaWiki 1.32. [Called from MassAction\Test\MassActionExtTest::setUp in /workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php at line 19]

/workspace/src/includes/debug/MWDebug.php:309
/workspace/src/includes/debug/MWDebug.php:241
/workspace/src/includes/GlobalFunctions.php:1119
/workspace/src/tests/phpunit/MediaWikiTestCase.php:814
/workspace/src/extensions/MassAction/tests/phpunit/MassActionExtTest.php:19
/workspace/src/tests/phpunit/MediaWikiTestCase.php:424
/workspace/src/maintenance/doMaintenance.php:94