Hi, I am struggling to use backfill on an asset that returns an output value. Whatever I am trying to do I get

dagster._core.errors.DagsterExecutionHandleOutputError: Error occurred while handling output "result" of step "test_output.construct_arguments":
The above exception was caused by the following exception:
AssertionError

Can anyone share an example code on how such case should look like? What should be the return value type?

mind sharing some code snippet for the asset definition?

yes, that is a snippet of test code which also gives the same error:

@asset(
    freshness_policy=FreshnessPolicy(maximum_lag_minutes=60),
    partitions_def=HourlyPartitionsDefinition(datetime(2023, 8, 1)),
    auto_materialize_policy=AutoMaterializePolicy.eager(max_materializations_per_minute=10),
)
def test_result(context) -> str:
    <http://context.log.info|context.log.info>(context.asset_partition_key_range_for_output().start)
    return context.asset_partition_key_range_for_output().start

p.s. i am currently on 1.4.3 version