Hello All.. I was checking the new open-source engine "Orion", but when I run the code I get the following error on the import statement

from prefect import flow

cannot import name 'ThreadedChildWatcher' from 'asyncio'

The code :

from prefect import flow
@flow
def common_flow(config: dict):
    print("I am a subgraph that shows up in lots of places!")
    intermediate_result = 42
    return intermediate_result

@flow
def main_flow():

    data = common_flow(config={})

# run the flow
flow_state = main_flow()

What Python version do you use? What’s your Orion version?

prefect --version

Can you import this function without errors?

from asyncio import get_running_loop

Often reinstalling Orion in a new virtual environment and resetting the DB helps in similar cases - you can: • delete the database file

~/.prefect/orion.db

. • reset the database with the CLI command

prefect orion database reset

• and then restart orion with

prefect orion start

• python version Python 3.10.1 •

from asyncio import get_running_loop

is running as well without any errors • there is no orion.db file in venv\Lib\site-packages\prefect directory • Finally I get the same error mentioned in the previous message when I run those commands

prefect orion database reset

prefect orion start

I believe the DB file is always located in ~/.prefect/orion.db regardless of whether you install Orion globally or in a virtual environment

Hi, I installed it on ubuntu env instead of windows, and worked as well

for posterity https://discourse.prefect.io/t/when-running-any-orion-flow-im-getting-the-error-cannot-[…]t-name-threadedchildwatcher-from-asyncio-how-to-fix-it/393