报错信息：

raise RuntimeError("Distributed package doesn't have NCCL " "built in")
RuntimeError: Distributed package doesn't have NCCL built in

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报错原因：

  windows系统不支持nccl，采用gloo；

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报错解决：

  代码开头添加：

import os
os.environ["PL_TORCH_DISTRIBUTED_BACKEND"] = "gloo"

  代码处修改：

dist.init_process_group(backend=backend, init_method="env://")
# 将原来的backend赋值为'gloo'
dist.init_process_group(backend='gloo', init_method="env://")

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