Why Exceptions will become warning in hydra?

[HydrogenSulfate]

For example:

# callback.py
class InitCallback(Callback):
    def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:
        # fix random seed for reproducibility
        prnt(config.seed)

# main.py
import hydra
import numpy as np
from omegaconf import DictConfig



@hydra.main(version_base=None, config_path="./", config_name="config.yaml")
def main(cfg: DictConfig):
    print("==Enter main==")


if __name__ == "__main__":
    main()

now if we dont define seed in yaml when and run python main.py, and terminal will show a warning of an raised error

/lib/python3.9/site-packages/hydra/_internal/callbacks.py:28: UserWarning: Callback InitCallback.on_job_start raised ConfigAttributeError: Key 'seed' is not in struct
    full_key: seed
    object_type=dict
  warnings.warn(
==Enter main==

So how can I disable the warning and change the exception back to a real Exception but not warning, because I want raise an exception to stop program rather than just a warning which will not stop program

[odelalleau]

I had a quick look at the code and it looks like there's currently no built-in way to raise the exception, as it's automatically converted into a warning.

What I believe you could do (untested) is to use warnings.filterwarnings() to match such warnings and turn them into errors.

[HydrogenSulfate]

Thanks for reply, as now I am curious about why Errors is degraded(regarded) as warnings in hydra? I guess this is somewhat unreasonable.

[odelalleau]

I agree it's probably not such a good idea as default behavior -- I don't know what was the original motivation behind it. Note though that the callback feature is still in "experimental" mode and thus subject to change.

[HydrogenSulfate]

I guess that Callback is not designed for(at least now) strong-validations or invasive modification, but for preprocess and postprocess which will not affect program running.

[HydrogenSulfate]

I agree it's probably not such a good idea as default behavior -- I don't know what was the original motivation behind it. Note though that the callback feature is still in "experimental" mode and thus subject to change.

I found this could work, hydra can not change exit to warnings:

# callback.py
class InitCallback(Callback):
    def on_job_start(self, config: DictConfig, **kwargs: Any) -> None:
        # fix random seed for reproducibility
+        try:
          print(config.seed)
+        except Exception as e:
+           print(e)
+           sys.exit(0)