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Hi all, for testing purposes is there any way to configure `.map`ped tasks to run sequentially instead of in parallel?

yes, you can. Just attach a local executor to your flow and then it will run sequentially for each mapped child task, here is an example:
```from prefect import task, Flow
from prefect.executors import LocalExecutor
import time


@task
def generate_random_numbers():
    return list(range(1, 5))


@task
def add_one(x):
    time.sleep(3)
    return x + 1


@task(log_stdout=True)
def print_results(res):
    print(res)


with Flow("mapping", executor=LocalExecutor()) as flow:
    numbers = generate_random_numbers()
    result = add_one.map(numbers)
    print_results(result)

if __name__ == "__main__":
    flow.run()```

Hmm, I am executing the flow with a `LocalExecutor()`

can you test the above example and confirm that it runs one after the other? For me it does. I believe you can use the same approach.

output:
```[2021-12-21 17:12:23+0100] INFO - prefect.FlowRunner | Beginning Flow run for 'mapping'
[2021-12-21 17:12:23+0100] INFO - prefect.TaskRunner | Task 'generate_random_numbers': Starting task run...
[2021-12-21 17:12:23+0100] INFO - prefect.TaskRunner | Task 'generate_random_numbers': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:23+0100] INFO - prefect.TaskRunner | Task 'add_one': Starting task run...
[2021-12-21 17:12:23+0100] INFO - prefect.TaskRunner | Task 'add_one': Finished task run for task with final state: 'Mapped'
[2021-12-21 17:12:23+0100] INFO - prefect.TaskRunner | Task 'add_one[0]': Starting task run...
[2021-12-21 17:12:26+0100] INFO - prefect.TaskRunner | Task 'add_one[0]': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:26+0100] INFO - prefect.TaskRunner | Task 'add_one[1]': Starting task run...
[2021-12-21 17:12:29+0100] INFO - prefect.TaskRunner | Task 'add_one[1]': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:29+0100] INFO - prefect.TaskRunner | Task 'add_one[2]': Starting task run...
[2021-12-21 17:12:32+0100] INFO - prefect.TaskRunner | Task 'add_one[2]': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:32+0100] INFO - prefect.TaskRunner | Task 'add_one[3]': Starting task run...
[2021-12-21 17:12:35+0100] INFO - prefect.TaskRunner | Task 'add_one[3]': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:35+0100] INFO - prefect.TaskRunner | Task 'print_results': Starting task run...
[2021-12-21 17:12:35+0100] INFO - prefect.TaskRunner | [2, 3, 4, 5]
[2021-12-21 17:12:35+0100] INFO - prefect.TaskRunner | Task 'print_results': Finished task run for task with final state: 'Success'
[2021-12-21 17:12:35+0100] INFO - prefect.FlowRunner | Flow run SUCCESS: all reference tasks succeeded```

Must be an issue somewhere else in my flow, I am getting the same output as you here