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

[caozhe19961226]

Traceback (most recent call last):
File "tools/train.py", line 244, in
main()
File "tools/train.py", line 233, in main
train_model(
File "/root/sim-Opera/./opera/apis/train.py", line 245, in train_model
runner.run(data_loaders, cfg.workflow)
File "/root/miniconda3/lib/python3.8/site-packages/mmcv/runner/epoch_based_runner.py", line 136, in run
epoch_runner(data_loaders[i], **kwargs)
File "/root/miniconda3/lib/python3.8/site-packages/mmcv/runner/epoch_based_runner.py", line 53, in train
self.run_iter(data_batch, train_mode=True, **kwargs)
File "/root/miniconda3/lib/python3.8/site-packages/mmcv/runner/epoch_based_runner.py", line 31, in run_iter
outputs = self.model.train_step(data_batch, self.optimizer,
File "/root/miniconda3/lib/python3.8/site-packages/mmcv/parallel/data_parallel.py", line 77, in train_step
return self.module.train_step(*inputs[0], **kwargs[0])
File "/root/mmdetection/mmdet/models/detectors/base.py", line 248, in train_step
losses = self(**data)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/module.py", line 1102, in _call_impl
return forward_call(*input, **kwargs)
File "/root/miniconda3/lib/python3.8/site-packages/mmcv/runner/fp16_utils.py", line 116, in new_func
return old_func(*args, **kwargs)
File "/root/mmdetection/mmdet/models/detectors/base.py", line 172, in forward
return self.forward_train(img, img_metas, **kwargs)
File "/root/sim-Opera/./opera/models/detectors/inspose.py", line 52, in forward_train
feat = self.extract_feat(img)
File "/root/mmdetection/mmdet/models/detectors/single_stage.py", line 43, in extract_feat
x = self.backbone(img)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/module.py", line 1102, in _call_impl
return forward_call(*input, **kwargs)
File "/root/sim-Opera/./opera/models/backbones/efficientformer2.py", line 659, in forward
x = self.patch_embed(x)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/module.py", line 1102, in _call_impl
return forward_call(*input, **kwargs)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/container.py", line 141, in forward
input = module(input)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/module.py", line 1102, in _call_impl
return forward_call(*input, **kwargs)
File "/root/miniconda3/lib/python3.8/site-packages/torch/nn/modules/batchnorm.py", line 732, in forward
world_size = torch.distributed.get_world_size(process_group)
File "/root/miniconda3/lib/python3.8/site-packages/torch/distributed/distributed_c10d.py", line 845, in get_world_size
return _get_group_size(group)
File "/root/miniconda3/lib/python3.8/site-packages/torch/distributed/distributed_c10d.py", line 306, in _get_group_size
default_pg = _get_default_group()
File "/root/miniconda3/lib/python3.8/site-packages/torch/distributed/distributed_c10d.py", line 410, in _get_default_group
raise RuntimeError(
RuntimeError: Default process group has not been initialized, please make sure to call init_process_group.

[y-arjun-y]

This is most likely due to the use of SyncBN instead of BatchNorm (source), try setting that to False in the main.py file.