2.9.28 vs 2.9.32 logs errors about: `unknown object type "SecretsManager" (not implemented)`

[John A Meinel]

As reported on Discourse

with an upgrade from 2.9.28 to 2.9.32 the Uniter agent starts complaining about:

unit-mysql-0: 09:27:25 ERROR juju.worker.dependency "uniter" manifold worker returned unexpected error: unknown object type "SecretsManager" (not implemented)

2.9.32 should not be introducing types for 2.9.28 that old versions of the agent do not understand.
We need to be careful here, because this looks like a case of older unit agents not being happy talking to a newer controller, which is very much a use case we intend to support with api facade versioning.
(It may be that the only fix is to rev 2.9.33 to a new facade version, and then only report the known types on the version that older agents (eg <=2.9.28) can handle.)

[John A Meinel (jameinel)]

https://discourse.charmhub.io/t/juju-units-die-with-unexpected-error-unknown-object-type-secretsmanager-not-implemented/6693

[Ian Booth (wallyworld)]

https://github.com/juju/juju/pull/14296