we learned that the authentication layer got a major overhaul in 1.27.
We are interested in Shibboleth-authentication  which derives from
AuthPlugin.php, deprecated and superseded by AuthManager.php. The last
version of this extension  is compatible with 1.26, but it does work
with 1.27 and above. It seems the project development has been stopped.
While you are accustomed with the new AuthManager classes, could you
help us by chance to get a new script working for 1.27? We found the
updating tips  but unfortunately we don't have any Mediawiki