[GitHub] adrianloy edited a comment on issue #9712: two consecutive backward cause error Check failed: type_ != nullptr The any container is empty requested

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adrianloy edited a comment on issue #9712: two consecutive backward cause error Check failed: type_ != nullptr The any container is empty requested
URL: https://github.com/apache/incubator-mxnet/issues/9712#issuecomment-457607617
 
 
   I got the same error and stumbled on this issue. I think another and maybe cleaner way that solved the error for me was to do
   `autograd.backward(list_of_loss_arrays)`
   In your case it should be possible to do
   `autograd.backward([t_xentropy_losses, s_xentropy_losses])`
   
   Just commenting to help others who come across this. If anyone knows why
   ```
   for loss in list_of_loss_arrays:
       loss.backward()
   ```
   doesnt work, let me know. Its weird because i got that code snippet from the official mxnet training script to train image classification networks from scratch.

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