Broken engine_exchangeTransitionConfigurationV1 RPC method

[jakubgs]

The beacon-node-sepolia-unstable-trial-0 node on linux-01.he-eu-hel1.nimbus.sepolia currently fails to start with:

{"lvl":"ERR","ts":"2023-03-06 09:46:10.586+00:00","msg":"Failed to exchange transition configuration","topics":"elmon","url":"ws:https://localhost:9568","err":"{\"code\":-32601,\"message\":\"'engine_exchangeTransitionConfigurationV1' is not a registered RPC method\",\"data\":null}"}
{"lvl":"FAT","ts":"2023-03-06 09:46:10.586+00:00","msg":"The Bellatrix hard fork requires the beacon node to be connected to a properly configured Engine API end-point. See https://nimbus.guide/merge.html for more details.","topics":"elmon"}

Which means that nimbus-eth1 running for the CL node is missing the correct support for Bellatrix fork.

[jakubgs]

Based on advice from @jangko I switched to using the Engine API WS port:

• status-im/infra-role-nimbus-eth1@7ff2c237 - service: support Engine API WS and HTTP ports
• status-im/infra-nimbus@03ef7c54 - nimbus.sepolia: use nimbus-eth1 Engine API WS port

But now the result is just the fatal failure:

{"lvl":"FAT","ts":"2023-03-06 10:30:53.429+00:00","msg":"The Bellatrix hard fork requires the beacon node to be connected to a properly configured Engine API end-point. See https://nimbus.guide/merge.html for more details.","topics":"elmon"}

But I guess the issue with missing engine_exchangeTransitionConfigurationV1 was not related to the ultimate failure state.

[jakubgs]

Actually, the error is still there, it just changed to invalid format string:

{                                                                                                                                      
  "lvl": "ERR",
  "ts": "2023-03-06 10:33:13.109+00:00",
  "msg": "Failed to exchange transition configuration",
  "topics": "elmon",
  "url": "ws:https://localhost:8573",
  "err": "{\"code\":-32000,\"message\":\"engine_exchangeTransitionConfigurationV1 raised an exception\",\"data\":\"invalid format string\"}"
}

So the method is not actually missing.