Hey folks I m seeing this rather cryptic pickle error when r

Question

Hey folks I m seeing this rather cryptic pickle error when running Prefect locally Prefect 2 4 0 Python 3 10 my code doesn t use Pydantic s `AnyUrl` or subclasses within the code do you have any idea what might be causing the pickle error

Krishnan Chandra · Answer

I think based on the error message that it has to do with Pydantic models being compiled with Cython <https pydantic docs helpmanual io install compiled with cython> but would be good to understand whether this is a known issue or not

Krishnan Chandra · Answer

Found it I think <https github com PrefectHQ prefect blob 3774c8b043dd3edd787314e89f312bd4382b92b1 src prefect utilities pydantic py L60 L63>

Zanie · Answer

Yeah this is some madness related to the compiled pydantic that I have a pretty low level workaround for so we can pickle our `Settings` object

Zanie · Answer

It looks like your task is raising an exception that contains a Pydantic model

Krishnan Chandra · Answer

Hmm that shouldn t be the case in fact the task doesn t raise an exception at all

Krishnan Chandra · Answer

Here s the full task definition and the error still occurs with this barebones implementation ``` task retries=3 retry delay seconds=10 def process record stream record type Type OpenAlexBaseModel records List OpenAlexBaseModel batch size PositiveInt = DEFAULT BATCH SIZE gt None print foo ```

Krishnan Chandra · Answer

The print statement never executes so I can only assume that the error gets thrown before the task begins executing