It's me again, and I managed to break something in another creative way.
Following the upgrade instructions going from Wagn 1.18.0 to Wagn 1.20.0 (gem update, bundle update, wagn update) causes rake to abort with the message:
missing card with codename: admin
This has left my Wagn at thornton2.com partially migrated and unable to render the *head card in raw view. I'm also getting an on-page error, alternately "missing card with codename: machine_cache" and "missing card with codename: script_pointer_config", and a dump visible only to the admin.
Any help would be greatly appreciated.