pytorch:1.0.0
model: faster-RCNN(https://github.com/facebookresearch/maskrcnn-benchmark 4)
when export to onnx, get the error:
……
File "/opt/conda/lib/python3.6/site-packages/torch/nn/modules/module.py", line 477, in _slow_forward
    result = self.forward(*input, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/maskrcnn_benchmark/modeling/detector/generalized_rcnn.py", line 50, in forward
    proposals, proposal_losses = self.rpn(images, features, targets)
  File "/opt/conda/lib/python3.6/site-packages/torch/nn/modules/module.py", line 487, in __call__
    result = self._slow_forward(*input, **kwargs)
  File "/opt/conda/lib/python3.6/site-packages/torch/nn/modules/module.py", line 464, in _slow_forward
    input_vars = tuple(torch.autograd.function._iter_tensors(input))
  File "/opt/conda/lib/python3.6/site-packages/torch/autograd/function.py", line 284, in _iter
    for var in _iter(o):
  File "/opt/conda/lib/python3.6/site-packages/torch/autograd/function.py", line 293, in _iter
    if condition_msg else ""))
ValueError: Auto nesting doesn't know how to process an input object of type maskrcnn_benchmark.structures.image_list.ImageList. Accepted types: Tensors, or lists/tuples of them