Add backend driver castellan for Oslo.config failed

I try to configure castellan into Oslo.config so that it retrieves the configuration values from a secret manager behind Castellan.

[DEFAULT]
config_source = secrets
[secrets]
config_file=/etc/glance/castellan.conf
mapping_file=/etc/glance/mapping.conf

I see python errors like this when I select driver=castellan:

Dec 25 23:48:30 ubuntu systemd[1]: Stopped OpenStack Image Service API.
Dec 25 23:48:30 ubuntu systemd[1]: Started OpenStack Image Service API.
Dec 25 23:48:31 ubuntu glance-api[814247]: Fatal Python error: Cannot recover from stack overflow.
Dec 25 23:48:31 ubuntu glance-api[814247]: Python runtime state: initialized

I try it in a few OpenStack versions but it can't fix it.