Self-query-retriever random errors

[MudassirAqeelAhmed]

Why do I often get this time of error inconsistently, using self-query-retriever with pinecone

File "/home/mudassiraqeel/langchain/langchain/chains/query_constructor/parser.py", line 129, in get_parser
    transformer = QueryTransformer(
TypeError: 'NoneType' object is not callable

This is the flow in it's entirety

<langchain.vectorstores.pinecone.Pinecone object at 0x7f0d5bfd88e0>
Traceback (most recent call last):
  File "/home/mudassiraqeel/langchain/main.py", line 61, in <module>
    retriever = SelfQueryRetriever.from_llm(llm, docsearch, document_content_description, metadata_field_info, verbose=True)
  File "/home/mudassiraqeel/langchain/langchain/retrievers/self_query/base.py", line 116, in from_llm
    llm_chain = load_query_constructor_chain(
  File "/home/mudassiraqeel/langchain/langchain/chains/query_constructor/base.py", line 125, in load_query_constructor_chain
    prompt = _get_prompt(
  File "/home/mudassiraqeel/langchain/langchain/chains/query_constructor/base.py", line 102, in _get_prompt
    output_parser = StructuredQueryOutputParser.from_components(
  File "/home/mudassiraqeel/langchain/langchain/chains/query_constructor/base.py", line 59, in from_components
    ast_parser = get_parser(
  File "/home/mudassiraqeel/langchain/langchain/chains/query_constructor/parser.py", line 129, in get_parser
    transformer = QueryTransformer(
TypeError: 'NoneType' object is not callable

[aarondiuz]

Installing the lark python library solved this issue for me.