No module named 'torch._dynamo'
If I choose INDUCTOR as dynamo backend(in fact, this is default config on my machine), it reports an errorNo module named ‘torch._dynamo’when executing following code:model, optimizer, data = accelerator.prepare(model, optimizer, data)I don’t know how to solve this problem, it seems not caused by a missing module. Also I found the code inside the accelerator.prepare() method that triggers the error is following:def prepare_model(self, model: torch.nn.Module, device_placement=None):
        """
        Prepares a PyTorch model for training in any distributed setup. It is recommended to use
        [`Accelerator.prepare`] instead.

        Args:
            model (`torch.nn.Module`):
                A PyTorch model to prepare. You don't need to prepare a model if it is used only for inference without
                any kind of mixed precision
            device_placement (`bool`, *optional*):
                Whether or not to place the model on the proper device. Will default to `self.device_placement`.
        """
        if device_placement is None:
            device_placement = self.device_placement and self.distributed_type != DistributedType.FSDP
        self._models.append(model)
        if device_placement:
            model = model.to(self.device)
        if self.state.dynamo_backend != DynamoBackend.NO:
            import torch._dynamo as dynamo // <- No module named 'torch._dynam'I use python 3.8, pytorch 1.12.1, accelerate 0.15.0.
2022-12-19T09:10:16Z
You need a nightly version of PyTorch for this feature.