Debug trials
Most trial failures come from one of three places: the image cannot start, the CLI arguments do not match, or no valid metrics were printed.
Start with the logs
The trial log should answer three questions:
- Did the container start?
- Did the program receive the expected
--hpo-*arguments? - Did stdout include at least one valid
hpo.metrics.*line?
Common failures
- Name
unknown argument- Type
- parser
- Description
The dashboard parameter name does not match your CLI parser.
- Name
missing metric- Type
- collector
- Description
The program finished without printing a valid
hpo.metrics.*line.
- Name
invalid JSON- Type
- collector
- Description
The value after
=is not JSON-serializable.
- Name
data not found- Type
- runtime
- Description
The image cannot access a dataset or configuration file it needs.
Debug locally
Run the same command shape on your machine before launching a large experiment.
docker run --rm your-image:latest \
--hpo-lookback-window=50 \
--hpo-risk-multiplier=1.4
Confirm the output contains metric lines:
hpo.metrics.objective=0.84
hpo.metrics.duration_seconds=42.1
For exact collector rules, see Metric format.