After upgrading rabbitmq-server from 3.10.8-1 to 3.11.1-1, RabbitMQ no longer starts.
The error is
Oct 1 10:10:05 rmq001-ed2prd rabbitmq-server[7511]: 2022-10-01 10:10:05.806947-05:00 [error] <0.230.0> Feature flags: `implicit_default_bindings`: required feature flag not enabled! It must be enabled before upgrading RabbitMQ.
Oct 1 10:10:05 rmq001-ed2prd rabbitmq-server[7511]: 2022-10-01 10:10:05.816830-05:00 [error] <0.230.0> Failed to initialize feature flags registry: {disabled_required_feature_flag,
Oct 1 10:10:05 rmq001-ed2prd rabbitmq-server[7511]: 2022-10-01 10:10:05.816830-05:00 [error] <0.230.0> implicit_default_bindings}
From what I could see, I should be able to add that feature flag by setting an environment variable at startup, such as RABBITMQ_FEATURE_FLAGS=implicit_default_bindings
I tried that, and received the exact same error.
This occurred on multiple machines for me last night, during our normal upgrade window, and I ended up reverting out the upgrade to get them functioning again.