#3859 [BUG] NotebookTask output types cannot actually be used Issue created by cosmicBboy Describe the bug `NotebookTask`s have 2 implicit outputs, on top of whatever the user outputs via

record_outputs

. This is a problem when we try to use the output of a notebook task, e.g. as the return output of the workflow

"""An example of how to use Jupyter Notebooks in your workflows."""

from pathlib import Path
from typing import Tuple

from flytekit import workflow, kwtypes
from flytekit.types.file import FlyteFile
from flytekit.types.structured import StructuredDataset
from flytekitplugins.papermill import NotebookTask


from workflows.example_00_intro import get_data


data_analysis_task = NotebookTask(
    name="workflows.data_analysis_task",
    notebook_path=str(
        Path(__file__).parent.parent.absolute()
        / "notebooks"
        / "data_analysis_task.ipynb"
    ),
    render_deck=True,
    disable_deck=False,
    inputs=kwtypes(structured_dataset=StructuredDataset),
    outputs=kwtypes(success=bool),
)

@workflow
def data_analysis_wf() -> Tuple[bool, FlyteFile, FlyteFile]:
    data = get_data()
    return data_analysis_task(structured_dataset=data)

Trying to

pyflyte register

this workflow will result on the following error:

RPC Failed, with Status: StatusCode.INTERNAL
        details: failed to compile workflow for [resource_type:WORKFLOW project:"flytesnacks" domain:"development" name:"workflows.example_notebook_tasks.data_analysis_wf" version:"uMWWUPTSJ7aW7oSK79MRDg==" ] with err failed to compile workflow with err Collected Errors: 4
        Error 0: Code: MismatchingTypes, Node Id: end-node, Description: Variable [out_nb] (type [blob:<format:"ipynb" > ]) doesn't match expected type [blob:<> ].
        Error 1: Code: MismatchingTypes, Node Id: end-node, Description: Variable [out_rendered_nb] (type [blob:<format:"html" > ]) doesn't match expected type [blob:<> ].
        Error 2: Code: ParameterNotBound, Node Id: end-node, Description: Parameter not bound [o1].
        Error 3: Code: ParameterNotBound, Node Id: end-node, Description: Parameter not bound [o2].

On the other hand, changing the signature to the one explicit output:

def data_analysis_wf() -> bool:

We get this error:

Failed with Unknown Exception <class 'AssertionError'> Reason: The Workflow specification indicates only one return value, received 3

Expected behavior Flyte should gracefully handle NotebookTask outputs somehow. Additional context to reproduce No response Screenshots No response Are you sure this issue hasn't been raised already? ☑︎ Yes Have you read the Code of Conduct? ☑︎ Yes flyteorg/flyte