My question in post

  
    
    
    Get error message "MaskedFill can't differentiate the mask" autograd
  
  
    My a program was able to run in earlier version 0.2.0+0eec332 of pytorch (date back to Oct. 6, 2017). 
Yesterday and today I upgraded my pytorch to the latest version from source, and now I can’t run 
the program. The error message I got is as follows 
File “/usr/local/lib/python3.5/dist-packages/torch/autograd/variable.py”, line 85, in setitem 
return MaskedFill.apply(self, key, value, True) 
File “/usr/local/lib/python3.5/dist-packages/torch/autograd/_functions/tensor.py”, line 483, in forward …
  


also related to custom autograd.Function and backward pass. Inspired by your code,
I modified my code and make it works now in the newer version of pytorch. However, I do not
clone the input during the forward pass, and it still works. Interesting, but also confusing me!