Not sure if we can do anything about this, but the file calendar/tests/externallib_tests.php did not match the suffix in the phpunit file (_test.php) so those tests are being skipped (and are failing since last year).

This is hard to solve - I tried some bash hacking of the run_phpunittests.sh script - but ended up finding lots of folders with definitions but no tests.

Will add my hacked script as a comment.