SDK - Run deployment fails unless flow imported

[Chris-Perkins]

Bug summary

Prefect fails to execute run_deployment if flow is not imported. The following pydantic error is raised:
State is not fully defined; you should define all referenced types, then call State.model_rebuild()

This code fails:

from prefect.deployments import run_deployment

run_deployment(name="<Deployment Name>", timeout=0)

But this code succeeds:

from prefect.deployments import run_deployment
from prefect import flow # NEW!

run_deployment(name="<Deployment Name>", timeout=0)

Version info

Version:             3.1.4
API version:         0.8.4
Python version:      3.11.4
Git commit:          78ee41cb
Built:               Wed, Nov 20, 2024 7:37 PM
OS/Arch:             darwin/arm64
Profile:             default
Server type:         cloud
Pydantic version:    2.10.1

Additional context

  File "/Users/nepperkins/Desktop/arnold/jobs/file.py", line 249, in <module>
    run_deployment(name=f"<My Deployment>", timeout=0)
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/utilities/asyncutils.py", line 399, in coroutine_wrapper
    return run_coro_as_sync(ctx_call())
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/utilities/asyncutils.py", line 243, in run_coro_as_sync
    return call.result()
           ^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/_internal/concurrency/calls.py", line 312, in result
    return self.future.result(timeout=timeout)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/_internal/concurrency/calls.py", line 182, in result
    return self.__get_result()
           ^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/3.11.4/lib/python3.11/concurrent/futures/_base.py", line 401, in __get_result
    raise self._exception
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/_internal/concurrency/calls.py", line 383, in _run_async
    result = await coro
             ^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/utilities/asyncutils.py", line 225, in coroutine_wrapper
    return await task
           ^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/utilities/asyncutils.py", line 389, in ctx_call
    result = await async_fn(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/client/utilities.py", line 103, in with_injected_client
    return await fn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/deployments/flow_runs.py", line 164, in run_deployment
    state=Scheduled(scheduled_time=scheduled_time),
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/prefect/states.py", line 609, in Scheduled
    return cls(type=StateType.SCHEDULED, state_details=state_details, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/pydantic/main.py", line 214, in __init__
    validated_self = self.__pydantic_validator__.validate_python(data, self_instance=self)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/nepperkins/.pyenv/versions/arnold/lib/python3.11/site-packages/pydantic/_internal/_mock_val_ser.py", line 100, in __getattr__
    raise PydanticUserError(self._error_message, code=self._code)
pydantic.errors.PydanticUserError: `State` is not fully defined; you should define all referenced types, then call `State.model_rebuild()`.

For further information visit https://errors.pydantic.dev/2.10/u/class-not-fully-defined