[Err]: RuntimeError: Default process group has not been initialized, please make sure to call init_process_group.

[Even]

RuntimeError: Default process group has not been initialized, please make sure to call init_process_group.
/usr/local/lib/python3.7/dist-packages/torch/nn/functional.py:718: UserWarning: Named tensors and all their associated APIs are an experimental feature and subject to change. Please do not use them for anything important until they are released as stable. (Triggered internally at /pytorch/c10/core/TensorImpl.h:1156.)
return torch.max_pool2d(input, kernel_size, stride, padding, dilation, ceil_mode)
Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/torch/nn/parallel/data_parallel.py", line 166, in forward
return self.module(*inputs[0], **kwargs[0])
File "/usr/local/lib/python3.7/dist-packages/torch/nn/modules/module.py", line 1051, in _call_impl
return forward_call(*input, **kwargs)
File "/mnt/diske/even/DenseCL/openselfsup/models/densecl.py", line 279, in forward
return self.forward_train(img, **kwargs)
File "/mnt/diske/even/DenseCL/openselfsup/models/densecl.py", line 200, in forward_train
im_k, idx_unshuffle = self._batch_shuffle_ddp(im_k)
File "/usr/local/lib/python3.7/dist-packages/torch/autograd/grad_mode.py", line 28, in decorate_context
return func(*args, **kwargs)
File "/mnt/diske/even/DenseCL/openselfsup/models/densecl.py", line 132, in _batch_shuffle_ddp
x_gather = concat_all_gather(x)
File "/usr/local/lib/python3.7/dist-packages/torch/autograd/grad_mode.py", line 28, in decorate_context
return func(*args, **kwargs)
File "/mnt/diske/even/DenseCL/openselfsup/models/densecl.py", line 297, in concat_all_gather
for _ in range(torch.distributed.get_world_size())
File "/usr/local/lib/python3.7/dist-packages/torch/distributed/distributed_c10d.py", line 748, in get_world_size
return _get_group_size(group)
File "/usr/local/lib/python3.7/dist-packages/torch/distributed/distributed_c10d.py", line 274, in _get_group_size
python-BaseException
default_pg = _get_default_group()
File "/usr/local/lib/python3.7/dist-packages/torch/distributed/distributed_c10d.py", line 358, in _get_default_group
raise RuntimeError("Default process group has not been initialized, "
RuntimeError: Default process group has not been initialized, please make sure to call init_process_group.

[齐晨旭]

modify the config
RESNETS:
NORM: "SyncBN"->''BN''