The new multi-environment system has broken the routing abilities in extensions.
PHP Fatal error: Class 'phpbb\routing\phpbb_url_generator' not found in /phpBB/phpbb/routing/router.php on line 319
Trying to visit a previously working URL for an extensions controller:
PHP Fatal error: Class 'phpbb\routing\phpbb_url_matcher' not found in /phpbb/routing/router.php on line 265
Acme-demo can be used to witness these errors in 3.2.0-dev