Atto's stupid tendency to create HTML like <p>You don't need a br at the end of a paragraph!</br></p> was breaking it.
1/ type/match/tests/walkthrough_test.php - tests are failing randomly, looks like some weird randomisation is going on there - see TODOs 2/ type/multianswer/tests/upgradelibnewqe_test.php contains invalid expected value - see TODO