PyCapsule Error from intermediary Node

[Radu1999]

Hi!
I was trying to build an intermediary node to perform prompt resolution (I want check if the prompt is too large and stop if thats the case rather than truncate).
But weirdly enough, i get this error:
Exception: Exception while running node 'Reader': cannot pickle 'PyCapsule' object.
The code is the following:

    def run(self, query: Optional[str] = None, file_paths: Optional[List[str]] = None,
            labels: Optional[MultiLabel] = None, documents: Optional[List[Document]] = None,
            memory: Optional[MemoryModule] = None,
            prompt_template: Optional[Union[str, PromptTemplate]] = None,
            meta: Optional[dict] = None, params: Optional[dict] = None, ) -> Tuple[Dict, str]:
        if not prompt_template:
            return {
                "query": query,
                "documents": documents,
                "meta": meta,
            }, "output_1"

        resolved_prompt = next(prompt_template.fill(documents=documents, query=query, meta=meta))
        prompt_template.prompt_text = resolved_prompt
        return {
            "query": query,
            "prompt_template": prompt_template
        }, "output_1"

Can you help with some ideas of why this is behaving in a weird manner? When i used the debugger the problem magically vanished.

Here is the entire error:

Traceback (most recent call last):
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/haystack/pipelines/base.py", line 556, in run
    node_output, stream_id = self._run_node(node_id, node_input)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/haystack/pipelines/base.py", line 469, in _run_node
    return self.graph.nodes[node_id]["component"]._dispatch_run(**node_input)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/haystack/nodes/base.py", line 201, in _dispatch_run
    return self._dispatch_run_general(self.run, **kwargs)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/haystack/nodes/base.py", line 219, in _dispatch_run_general
    arguments = deepcopy(kwargs)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 146, in deepcopy
    y = copier(x, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 231, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 172, in deepcopy
    y = _reconstruct(x, memo, *rv)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 271, in _reconstruct
    state = deepcopy(state, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 146, in deepcopy
    y = copier(x, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 231, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 146, in deepcopy
    y = copier(x, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 231, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 146, in deepcopy
    y = copier(x, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 231, in _deepcopy_dict
    y[deepcopy(key, memo)] = deepcopy(value, memo)
  File "/Users/raduchivereanu/anaconda3/lib/python3.10/copy.py", line 161, in deepcopy
    rv = reductor(4)
TypeError: cannot pickle 'PyCapsule' object

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/flask/app.py", line 2190, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/flask/app.py", line 1486, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/flask/app.py", line 1484, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/flask/app.py", line 1469, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/src/sherlock/web/custom_decorators.py", line 27, in wrapper
    return func(*args, **kwargs)
  File "/Users/raduchivereanu/Desktop/sherlock_backend/src/sherlock/web/functions.py", line 182, in query_kb
    answer = qa_pipeline.run(
  File "/Users/raduchivereanu/Desktop/sherlock_backend/venv/lib/python3.10/site-packages/haystack/pipelines/base.py", line 563, in run
    raise Exception(
Exception: Exception while running node 'Reader': cannot pickle 'PyCapsule' object
Enable debug logging to see the data that was passed when the pipeline failed.

THANKS!

[anakin87]

Hey!

Very strange and never seen before in Haystack...

I would suggest reinstalling Haystack in a clean virtual environment and see if the issue persists.

I found similar errors around the web, but they do not seem related.