RuntimeWarning: coroutine 'Variable.aget' was never awaited

[EmilRex]

Bug summary

When deploying a flow that gets a variable in the root of the file, a runtime warning is raised. This is not the case when directly invoking the flow:

# prefect variable set foo bar
from prefect import flow, get_run_logger
from prefect.variables import Variable

var = Variable.get("foo")

@flow
def hello():
    logger = get_run_logger()
    logger.info(f"Hello, {var}!")

if __name__ == "__main__":
    hello()

Running the flow works as expected:

$ python flow.py
13:28:01.628 | INFO    | Flow run 'ancient-labradoodle' - Beginning flow run 'ancient-labradoodle' for flow 'hello'
13:28:01.631 | INFO    | Flow run 'ancient-labradoodle' - View at https://app.prefect.cloud/account/0ff44498-d380-4d7b-bd68-9b52da03823f/workspace/6bf6d7a9-ab18-4942-9315-349d4f1fef34/runs/flow-run/eb104141-322a-43cd-b4c0-999d445c2ac4
13:28:01.632 | INFO    | Flow run 'ancient-labradoodle' - Hello, bar!
13:28:01.781 | INFO    | Flow run 'ancient-labradoodle' - Finished in state Completed()

However, deploying it fails:

$ prefect --no-prompt deploy flow.py:hello --name served --pool process
Unable to read the specified config file. Reason: [Errno 2] No such file or directory: 'prefect.yaml'. Skipping.
Your Prefect workers will attempt to load your flow from: /Users/emilchristensen/github/examples/flow.py. To see more options for 
managing your flow's code, run:

        $ prefect init

╭────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Deployment 'hello/served' successfully created with id '15f1662b-a874-452b-b366-826d3ddb04b5'.                                                     │
╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

View Deployment in UI: https://app.prefect.cloud/account/0ff44498-d380-4d7b-bd68-9b52da03823f/workspace/6bf6d7a9-ab18-4942-9315-349d4f1fef34/deployments/deployment/15f1662b-a874-452b-b366-826d3ddb04b5


To schedule a run for this deployment, use the following command:

        $ prefect deployment run 'hello/served'

sys:1: RuntimeWarning: coroutine 'Variable.aget' was never awaited
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

The last two lines specifically are what seem to problematic:

sys:1: RuntimeWarning: coroutine 'Variable.aget' was never awaited
RuntimeWarning: Enable tracemalloc to get the object allocation traceback

Version info

Version:             3.1.15
API version:         0.8.4
Python version:      3.12.8
Git commit:          3ac3d548
Built:               Thu, Jan 30, 2025 11:31 AM
OS/Arch:             darwin/arm64
Profile:             dev
Server type:         cloud
Pydantic version:    2.10.6
Integrations:
  prefect-docker:    0.6.2

Additional context

No response

[cicdw]

I see, that's tricky - the recommended workaround for now is to set

var = Variable.get("foo", _sync=True)

[EmilRex]

I see, that's tricky - the recommended workaround for now is to set

var = Variable.get("foo", _sync=True)

Ah, I didn't realize you could do that... that's a solid work around, thank you @cicdw!