runtime error on pytorch 1.10

[saintazunya]

Describe the bug
A clear and concise description of what the bug is.

Environment

• Your operating system and version: ubuntu focal
• Your python version: 3.8
• Your PyTorch version: 1.10
• How did you install python (e.g. apt or pyenv)? Did you use a virtualenv?: conda
• Have you tried using latest bagua master (python3 -m pip install --pre bagua)?: yes

Reproducing

Please provide a minimal working example. This means the runnable code.

Please also write what exact commands are required to reproduce your results.

Just run Bagua example's benchmark script.

Additional context
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Traceback (most recent call last):
  File "/io/bagua/bagua/examples/benchmark/synthetic_benchmark.py", line 154, in <module>
    model = model.with_bagua([optimizer], algorithm)
  File "/opt/conda/envs/pytorch/lib/python3.9/site-packages/bagua/torch_api/distributed.py", line 396, in with_bagua
    self._bagua_init_algorithm()
  File "/opt/conda/envs/pytorch/lib/python3.9/site-packages/bagua/torch_api/distributed.py", line 441, in _bagua_init_algorithm
    self._bagua_broadcast_parameters()
  File "/opt/conda/envs/pytorch/lib/python3.9/site-packages/bagua/torch_api/distributed.py", line 213, in _bagua_broadcast_parameters
    broadcast(state, src=0)
  File "/opt/conda/envs/pytorch/lib/python3.9/site-packages/bagua/torch_api/communication.py", line 523, in broadcast
    comm.broadcast(tensor.to_bagua_tensor().bagua_backend_tensor(), src)
  File "/opt/conda/envs/pytorch/lib/python3.9/site-packages/bagua/torch_api/tensor.py", line 79, in to_bagua_tensor
    new_tensor = torch.Tensor(cdata=self._cdata)
RuntimeError: Creating a new Tensor subclass Tensor but the raw Tensor object is already associated to a python object of type Parameter
Killing subprocess 764

[Shawn]

It seems that PyTorch 1.10 refuses to create new tensor from cdata pointer.

This will be fixed in next release.