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

[km1562]

when I use single GPU, the ABC will produce the error,
I find the answer on the Internet,
it's the reason that ABC use the synbatchnorm,
So,
when use the single GPU,
you need to init the process_group,
maybe you can updata the code to main
————————————————————

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cuda_num = os.environ['CUDA_VISIBLE_DEVICES']
cuda_num_list = list(cuda_num.split(","))
if len(cuda_num_list) == 1:
import torch.distributed as dist

  dist.init_process_group(backend='nccl', init_method='tcp://localhost:23456', rank=0, world_size=1)
  print("already init\n")

[kimile599]

Update the solution worked on colab
cuda_num = os.environ['CUDA_VISIBLE_DEVICES'] casue keyerrors
so i manually changed cuda_num="0"

cuda_num_list = list(cuda_num.split(","))
if len(cuda_num_list) == 1:
import torch.distributed as dist