Error with pacconv: trying to differentiate twice a function that was marked with @once_differentiable

[maxbeauchamp]

Hi,

I tried to use pacnet in one my code but when using the function :
pacconv = PacConv2d(in_ch, out_ch, f)
out_pac = pacconv(input, None, guide_k)
In my case input has shape(2,1,200,200) and guide_k (2,1,3,3,200,200).

The forward pass of my code is ok but when computing the backward pass I got this error message:
trying to differentiate twice a function that was marked with @once_differentiable

Do you have any idea of this issue ? Replacing the pacconv by a simple convolution layer removes the error.

Thanks in advance