When reasoning is set to xhigh codex-acp fails to start with:

codex-acp
2025-11-20T08:38:27.332977Z ERROR codex_core::config: Failed to deserialize overridden config: unknown variant xhigh, expected one of none, minimal, low, medium, high
in model_reasoning_effort

Error: error loading config: unknown variant xhigh, expected one of none, minimal, low, medium, high
in model_reasoning_effort