Solved by leowalkling in post #4 
              
              
                I found out, that in PyTorch 1.2, the default behavior is not to allow alias specifications, leading to a segfault. 
This can be changed, but alias specifications are not allowed for third-party extensions as stated in the error message: 
RuntimeError: node->kind().is_prim() || node->kind().is_aten(…