Sorry, I re-compile the project and  no more free() problem.
It is another one 
operation failed in interpreter:
op_version_set = 0
def forward(self,
input: Tensor) -> Tensor:
if bool(torch.gt(torch.sum(input), 0)):
output = torch.mv(self.weight, input)
~~~~~~~~ <— HERE
else:
output_2 = torch.add(self.weight, input, alpha=1)
output = output_2
return output
Abandon (core dumped)