backward errors

[hsl20130659]

output = right_pool.backward(input, grad_output)[0]
RuntimeError: Expected object of type Variable but found type CPUFloatType for argument #0 'result' (checked_cast_variable at /pytorch/torch/csrc/autograd/VariableTypeManual.cpp:196)
frame #0: std::function<std::string ()>::operator()() const + 0x11 (0x7f071af0d021 in /usr/local/lib/python3.5/dist-packages/torch/lib/libc10.so)
frame #1: c10::Error::Error(c10::SourceLocation, std::string const&) + 0x2a (0x7f071af0c8ea in /usr/local/lib/python3.5/dist-packages/torch/lib/libc10.so)
frame #2: torch::autograd::VariableType::checked_cast_variable(at::Tensor&, char const*, int) + 0x16e (0x7f0719cb51be in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #3: torch::autograd::VariableType::unpack(at::Tensor&, char const*, int) + 0x9 (0x7f0719cb5259 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #4: torch::autograd::VariableType::s__th_gt_out(at::Tensor&, at::Tensor const&, at::Tensor const&) const + 0x44 (0x7f0719bf1dc4 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #5: at::TypeDefault::_th_gt_out(at::Tensor&, at::Tensor const&, at::Tensor const&) const + 0x205 (0x7f071bca39b5 in /usr/local/lib/python3.5/dist-packages/torch/lib/libcaffe2.so)
frame #6: at::TypeDefault::gt_out(at::Tensor&, at::Tensor const&, at::Tensor const&) const + 0x62 (0x7f071bc81102 in /usr/local/lib/python3.5/dist-packages/torch/lib/libcaffe2.so)
frame #7: torch::autograd::VariableType::gt_out(at::Tensor&, at::Tensor const&, at::Tensor const&) const + 0x152 (0x7f0719c3df02 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #8: pool_backward(at::Tensor, at::Tensor) + 0x4ae (0x7f07108c957e in /usr/local/lib/python3.5/dist-packages/cpools-0.0.0-py3.5-linux-x86_64.egg/right_pool.cpython-35m-x86_64-linux-gnu.so)
frame #9: + 0x137c4 (0x7f07108d57c4 in /usr/local/lib/python3.5/dist-packages/cpools-0.0.0-py3.5-linux-x86_64.egg/right_pool.cpython-35m-x86_64-linux-gnu.so)
frame #10: + 0x138de (0x7f07108d58de in /usr/local/lib/python3.5/dist-packages/cpools-0.0.0-py3.5-linux-x86_64.egg/right_pool.cpython-35m-x86_64-linux-gnu.so)
frame #11: + 0x117e6 (0x7f07108d37e6 in /usr/local/lib/python3.5/dist-packages/cpools-0.0.0-py3.5-linux-x86_64.egg/right_pool.cpython-35m-x86_64-linux-gnu.so)
frame #12: PyCFunction_Call + 0x77 (0x4ea137 in /usr/bin/python3.5)
frame #13: PyEval_EvalFrameEx + 0x614 (0x536d94 in /usr/bin/python3.5)
frame #14: PyEval_EvalCodeEx + 0x13b (0x540b0b in /usr/bin/python3.5)
frame #15: /usr/bin/python3.5() [0x4ec2e3]
frame #16: PyObject_Call + 0x47 (0x5c20e7 in /usr/bin/python3.5)
frame #17: PyEval_EvalFrameEx + 0x252b (0x538cab in /usr/bin/python3.5)
frame #18: PyEval_EvalCodeEx + 0x13b (0x540b0b in /usr/bin/python3.5)
frame #19: /usr/bin/python3.5() [0x4ec2e3]
frame #20: PyObject_Call + 0x47 (0x5c20e7 in /usr/bin/python3.5)
frame #21: /usr/bin/python3.5() [0x4fbfce]
frame #22: PyObject_Call + 0x47 (0x5c20e7 in /usr/bin/python3.5)
frame #23: PyEval_CallObjectWithKeywords + 0x30 (0x534870 in /usr/bin/python3.5)
frame #24: torch::autograd::PyFunction::apply(std::vector<torch::autograd::Variable, std::allocatortorch::autograd::Variable >&&) + 0x193 (0x7f07537762b3 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch_python.so)
frame #25: torch::autograd::Engine::evaluate_function(torch::autograd::FunctionTask&) + 0x39e (0x7f0719a376ee in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #26: torch::autograd::Engine::thread_main(torch::autograd::GraphTask*) + 0xc0 (0x7f0719a39850 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #27: torch::autograd::Engine::thread_init(int) + 0xc7 (0x7f0719a36377 in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch.so.1)
frame #28: torch::autograd::python::PythonEngine::thread_init(int) + 0x2a (0x7f0753770dfa in /usr/local/lib/python3.5/dist-packages/torch/lib/libtorch_python.so)
frame #29: + 0xb8c80 (0x7f071aa28c80 in /usr/lib/x86_64-linux-gnu/libstdc++.so.6)
frame #30: + 0x76ba (0x7f0762d626ba in /lib/x86_64-linux-gnu/libpthread.so.0)
frame #31: clone + 0x6d (0x7f0762a9841d in /lib/x86_64-linux-gnu/libc.so.6)

does someone meet this pronblem ? and how to solve
this problem

[adhereyuyu]

have you solve the problem?