class MultipleTaskLoop(Task):
    def run(self):
        # loop_res = prefect.context.get("task_loop_result", 1)
        # print(loop_res)

        with Flow('hello-world') as flow:
            a = task_a()
            task_b(a)

        subflow_res = flow.run()
        new_res = subflow_res.result[task_b]._result.value
        print(new_res)

        if new_res:
            return new_res
        raise LOOP(result=new_res)


@task(log_stdout=True)
def task_a():
    return "A"


@task(log_stdout=True)
def task_b(a_arg):
    print(a_arg)
    print("B")
    r = randrange(5)
    if r < 3:
        print("False")
        return False
    print("True")
    return True


with Flow("parent-flow") as parent_flow:
    loop_task = MultipleTaskLoop()
    loop_task()

Unexpected error while running flow: KeyError('Task slug MultipleTaskLoop-1 is not found in the current Flow. This is usually caused by a mismatch between the flow version stored in the Prefect backend and the flow that was loaded from storage.\n- Did you change the flow without re-registering it?\n- Did you register the flow without updating it in your storage location (if applicable)?')
Traceback (most recent call last):
  File "/Users/martha/Documents/prefect-prototype/venv/lib/python3.9/site-packages/prefect/engine/cloud/flow_runner.py", line 398, in initialize_run
    task = tasks[task_run.task_slug]
KeyError: 'MultipleTaskLoop-1'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/martha/Documents/prefect-prototype/venv/lib/python3.9/site-packages/prefect/engine/flow_runner.py", line 264, in run
    state, task_states, run_context, task_contexts = self.initialize_run(
  File "/Users/martha/Documents/prefect-prototype/venv/lib/python3.9/site-packages/prefect/engine/cloud/flow_runner.py", line 400, in initialize_run
    raise KeyError(
KeyError: 'Task slug MultipleTaskLoop-1 is not found in the current Flow. This is usually caused by a mismatch between the flow version stored in the Prefect backend and the flow that was loaded from storage.\n- Did you change the flow without re-registering it?\n- Did you register the flow without updating it in your storage location (if applicable)?'

create_flow_run

wait_for_flow_run