Standalone: doesn't install because of missing session class
Standalone installer (web based) fails because it tries to start session before it's found the standaloneusers/ session class; presumably, before it's booted extensions(possibly?).
Note it is possible to install from civibuild, but the other methods don't work.
See @clarkac https://chat.civicrm.org/civicrm/pl/neac84z6ztrymendzimmtqa18a
Fatal error: Uncaught Error:
Class "Civi\Standalone\SessionHandler" not found in
.../web/core/CRM/Utils/System/Standalone.phpfollowed by a stack trace followed by:
thrown in .../web/core/CRM/Utils/System/Standalone.php on line 556