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no, when i cancel, i dont have messages from on_cancel_fn()

• what version of prefect?
• how are you attempting to cancel the flow run? ie UI or API or something else

for clarification i got only this:
11:48:49.945 | INFO    | prefect.workers.process.processworker f801058e-4b7f-43b4-87e8-854539e9ff3c - Found 1 flow runs awaiting cancellation.
11:48:50.047 | INFO    | prefect.flow_runs.worker - Cancelled flow run '785948b5-9082-4695-bc44-b123dd472f9e'!
11:48:50.263 | ERROR   | prefect.flow_runs.worker - Process 12936 exited with status code: 3

Hi Sergei! If you're using a Process worker, I believe you're running into a similar issue that <https://github.com/PrefectHQ/prefect/issues/14690|this user reported in GitHub>. The cancellation hook does seem to work reliably when using `.serve()` like so:
```from prefect import flow
from prefect.logging.loggers import flow_run_logger
import time

def log_something(flow, flow_run, state):
    flow_run_logger(flow_run, flow).info(f"Flow {flow.name} cancelled")

@flow(on_cancellation=[log_something])
def test_flow():
    time.sleep(30)
    return 42

if __name__=="__main__":
    test_flow.serve(name="my-cancelled-flow")```