https://gerrit.wikimedia.org/r/#/c/mediawiki/libs/RemexHtml/+/592170/
https://integration.wikimedia.org/ci/job/composer-package-php74-docker/609/console
I won't paste them all, but...
03:11:36 There were 13268 errors: 03:11:36 03:11:36 1) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: PLAINTEXT content model flag" ('PLAINTEXT state', 'plaintext', '<head>&body;', array(array('Character', '<head>&body;'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 2) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (RCDATA state)" ('RCDATA state', 'xmp', 'foo</xmp>', array(array('Character', 'foo'), array('EndTag', 'xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 3) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (RAWTEXT state)" ('RAWTEXT state', 'xmp', 'foo</xmp>', array(array('Character', 'foo'), array('EndTag', 'xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 4) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (case-insensitivity) (RCDATA state)" ('RCDATA state', 'xmp', 'foo</xMp>', array(array('Character', 'foo'), array('EndTag', 'xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 5) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (case-insensitivity) (RAWTEXT state)" ('RAWTEXT state', 'xmp', 'foo</xMp>', array(array('Character', 'foo'), array('EndTag', 'xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 6) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (ending with space) (RCDATA state)" ('RCDATA state', 'xmp', 'foo</xmp ', array(array('Character', 'foo'), 'ParseError')) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 7) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (ending with space) (RAWTEXT state)" ('RAWTEXT state', 'xmp', 'foo</xmp ', array(array('Character', 'foo'), 'ParseError')) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 8) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (ending with EOF) (RCDATA state)" ('RCDATA state', 'xmp', 'foo</xmp', array(array('Character', 'foo</xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 9) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (ending with EOF) (RAWTEXT state)" ('RAWTEXT state', 'xmp', 'foo</xmp', array(array('Character', 'foo</xmp'))) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135 03:11:36 03:11:36 10) RemexHtml\Tokenizer\TokenizerTest::testDefault with data set "contentModelFlags.test: End tag closing RCDATA or RAWTEXT (ending with slash) (RCDATA state)" ('RCDATA state', 'xmp', 'foo</xmp/', array(array('Character', 'foo'), 'ParseError')) 03:11:36 Trying to access array offset on value of type bool 03:11:36 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:111 03:11:36 /src/tests/phpunit/Tokenizer/TokenizerTest.php:135