I have a core-dump back trace, what's the possible reason?

[wangty6]

`
Program terminated with signal 11, Segmentation fault.
#0 0x0000000000fddfae in hnswlib::HierarchicalNSW::searchBaseLayerST(unsigned int, void*, unsigned long) () at /home/bigo/recommend/recsys_framework/thirdparty/include/hnsw/hnswalg.h:253

#1 0x0000000000fdc8e3 in hnswlib::HierarchicalNSW::searchKnn(void*, unsigned long) () at /home/bigo/recommend/recsys_framework/thirdparty/include/hnsw/hnswalg.h:704

#2 0x0000000000fdafc7 in brec::KnnIndex::knnQuery(std::vector<std::pair<float, unsigned long>, std::allocator<std::pair<float, unsigned long> > >&, std::vector<float, std::allocator > const&, unsigned long) () at /home/bigo/recommend/recsys_framework/brec/knn/knn_index.h:217

#3 0x0000000000fd90f1 in server::recsys::KnnModel::knnQuery(std::vector<std::pair<float, unsigned long>, std::allocator<std::pair<float, unsigned long> > >&, std::vector<float, std::allocator > const&, int) () at /home/bigo/recommend/recommend_recall_d/src/models/knn_model.cpp:51
`

[wangty6]

I know it's because the graph is empty