Key for metric doesn't seem to be correct

[astro-kevin]

I'm trying to use Ray to do a Hyperparameter search via the sklearn API. In there, one of the callback function RayTrainReportCallback requires the key of the XGBoost metric. Since I'm using XGBoostRegressor, I would think the key should be validation_0-rmse. But this, and all other variations of that throw a key error.

Can someone tell me what the correct key should be, or at least how to reveal the dictionary of metrics?

[trivialfis]

Could you please open the issue in xgboost_ray? I'm not familiar with the ray interface.

[astro-kevin]

I don't believe xgboost_ray is still supported. I have been having trouble using that package (which you'll see the latest issue being created by me too). I've since moved to use xgboost (with the sklearn API) with ray/ray-tune. Since that requires access to a key for a metric in xgboost, it should belong to the xgboost repo? I can open an issue in ray too, but I don't know if this belongs there more.

[trivialfis]

Could you please share a snippet that I can run and debug? I need a starting point to see what's happening.