notes:
"""
Hi Jintao, just an update that I've found the server issue in SERVER-119629 and am working on a fix. also, when I was testing, I found a possible $rerank bug: if I remove the $vectorSearch pipeline from the $rankFusion that precedes $rerank in the failing query, the query fails with

"Failed to send request: HTTP status client error (400 Bad Request) for url (https://api.voyageai.com/v1/rerank)"
I think this is probably related to the fact that the $search query by itself returns 0 documents, so $rerank receives 0 input documents
""""