OnnxToCaffe2 - Incompatible ConvTranspose operator

Hello, noob here - apologies in advance if this is a stupid question.

I’m attempting to load an ONNX model in Caffe2 using: caffe2::onnx::Caffe2Backend::Prepare(const std::string & onnx_model_str, const std::string & device, const std::vector<caffe2::onnx::Caffe2Ops,std::allocatorcaffe2::onnx::Caffe2Ops> & extras)

I’m getting the following error:
“Don’t know how to map unexpected argument ‘group’ (from operator ConvTranspose)”.

If I load the same model as Caffe2 prototext (by converting offline to init/predict via c2.onnx_graph_to_caffe2_net), I don’t have any issues.

Investigating the error, it seems that Caffe2’s ConvTranspose expects the following args: legacy_pad, kernels, strides, pads, adjs, order, shared_buffer, no_bias, whereas ONNX’s ConvTranspose assumes the following: auto_pad, dilations, group, kernel_shape, output_padding, output_shape, pads, strides.

Looks like the ‘group’ argument was added on April 4 2019 to the Caffe2 operator :

But the Caffe2 ONNX backend schema wasn’t changed and it doesn’t seem to have kept up with ONNX itself.

Questions:

  1. Is my interpretation correct?
  2. If yes, is OnnxNodeToCaffe2Ops (caffe2\onnx\backend.cc) maintained/supported? Can I rely on loading ONNX models directly in Caffe2?

Thanks so much!