Same problem here.
I also found a similar discussion:

  
    
    
    Can ScriptModule be used for training? 
  
  
    Can ScriptModule be used for training? The reason we ask this question is that we found some source code related back propagation in torch.jit. https://github.com/pytorch/pytorch/blob/master/torch/csrc/jit/autodiff.cpp#L1151
  


Any update?