I have one onnx file of trained from yolo8. I want to use it in burn, as the backend. Then i import the onnx file , and an error is throwed. The error like this:

checking outputs DEBUG burn_import::onnx::from_onnx: output name: /model.22/Shape_4_output_0 DEBUG burn_import::onnx::proto_conversion: Converting ONNX node with type "Concat" DEBUG burn_import::onnx::from_onnx: renaming node "/model.22/Concat_3" ERROR burn_import::logger: PANIC => panicked at /home/lin/.cargo/registry/src/mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd/burn-import-0.13.0/src/onnx/dim_inference.rs:178:10: calledOption::unwrap()on aNone` value

--- stderr
thread 'main' panicked at /home/lin/.cargo/registry/src/mirrors.tuna.tsinghua.edu.cn-df7c3c540f42cdbd/burn-import-0.13.0/src/onnx/dim_inference.rs:178:10:
called Option::unwrap() on a None value`

This is a bug or not , i don't know. So, anyone can help me , please. thanks .