Hi there! I have reproduced minimal example of failing combination.

@task
def fail_task() -> List[Any]:
    return []

@workflow
def fail_workflow():
    fail_task()

Using flytekit 1.5.0 and 1.6.0b0 there is error:

Traceback (most recent call last):

      File "/opt/venv/lib/python3.8/site-packages/flytekit/exceptions/scopes.py", line 165, in system_entry_point
        return wrapped(*args, **kwargs)
      File "/opt/venv/lib/python3.8/site-packages/flytekit/core/base_task.py", line 587, in dispatch_execute
        raise TypeError(msg) from e

Message:

    Failed to convert outputs of task 'pipelines.parallel.fail_task' at position 0:
  range() arg 3 must not be zero

SYSTEM ERROR! Contact platform administrators.

In flytekit 1.4.2 the same code works. Does anyone know how to fix that in newer revisions of flytekit?

Hmm interesting thank you for sharing

looking.