[ Core] cannot serialize polars.LazyFrame

[jmakov]

What happened + What you expected to happen

Cannot send polars.LazyFrame to worker. Traceback:

---> 38 self._ref_lf = ray.put(lf)
     39 self._refs_task = []

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/auto_init_hook.py:21, in wrap_auto_init.<locals>.auto_init_wrapper(*args, **kwargs)
     18 @wraps(fn)
     19 def auto_init_wrapper(*args, **kwargs):
     20     auto_init_ray()
---> 21     return fn(*args, **kwargs)

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/client_mode_hook.py:103, in client_mode_hook.<locals>.wrapper(*args, **kwargs)
    101     if func.__name__ != "init" or is_client_mode_enabled_by_default:
    102         return getattr(ray, func.__name__)(*args, **kwargs)
--> 103 return func(*args, **kwargs)

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/worker.py:2720, in put(value, _owner)
   2718 with profiling.profile("ray.put"):
   2719     try:
-> 2720         object_ref = worker.put_object(value, owner_address=serialize_owner_address)
   2721     except ObjectStoreFullError:
   2722         logger.info(
   2723             "Put failed since the value was either too large or the "
   2724             "store was full of pinned objects."
   2725         )

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/worker.py:764, in Worker.put_object(self, value, object_ref, owner_address, _is_experimental_channel)
    759     assert (
    760         object_ref is None
    761     ), "Local Mode does not support inserting with an ObjectRef"
    763 try:
--> 764     serialized_value = self.get_serialization_context().serialize(value)
    765 except TypeError as e:
    766     sio = io.StringIO()

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/serialization.py:519, in SerializationContext.serialize(self, value)
    517     return RawSerializedObject(value)
    518 else:
--> 519     return self._serialize_to_msgpack(value)

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/serialization.py:497, in SerializationContext._serialize_to_msgpack(self, value)
    495 if python_objects:
    496     metadata = ray_constants.OBJECT_METADATA_TYPE_PYTHON
--> 497     pickle5_serialized_object = self._serialize_to_pickle5(
    498         metadata, python_objects
    499     )
    500 else:
    501     pickle5_serialized_object = None

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/serialization.py:444, in SerializationContext._serialize_to_pickle5(self, metadata, value)
    442 except Exception as e:
    443     self.get_and_clear_contained_object_refs()
--> 444     raise e
    445 finally:
    446     self.set_out_of_band_serialization()

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/_private/serialization.py:439, in SerializationContext._serialize_to_pickle5(self, metadata, value)
    437 try:
    438     self.set_in_band_serialization()
--> 439     inband = pickle.dumps(
    440         value, protocol=5, buffer_callback=writer.buffer_callback
    441     )
    442 except Exception as e:
    443     self.get_and_clear_contained_object_refs()

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/cloudpickle/cloudpickle.py:1479, in dumps(obj, protocol, buffer_callback)
   1477 with io.BytesIO() as file:
   1478     cp = Pickler(file, protocol=protocol, buffer_callback=buffer_callback)
-> 1479     cp.dump(obj)
   1480     return file.getvalue()

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/ray/cloudpickle/cloudpickle.py:1245, in Pickler.dump(self, obj)
   1243 def dump(self, obj):
   1244     try:
-> 1245         return super().dump(obj)
   1246     except RuntimeError as e:
   1247         if len(e.args) > 0 and "recursion" in e.args[0]:

File ~/mambaforge-pypy3/envs/test/lib/python3.11/site-packages/polars/lazyframe/frame.py:324, in LazyFrame.__getstate__(self)
    323 def __getstate__(self) -> bytes:
--> 324     return self._ldf.__getstate__()

RuntimeError: BindingsError: "Value(\"the enum variant Expr::RenameAlias cannot be serialized\")"```


### Versions / Dependencies

ray 2.31.0
python 3.11.9

### Reproduction script

import polars
import ray


lf = polars.LazyFrame(...)
ray.put(lf)

### Issue Severity

None

[jjyao]

Is polars.LazyFrame pickable? If not then Ray cannot serialize it and you can reach out to polars people to make it pickable.