stacktrace for https://github.com/pytorch/xla/pull/4289

gistfile1.txt

Thread 1880 "python3" hit Catchpoint 1 (exception thrown), 0x00007ffff35d3afd in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0  0x00007ffff35d3afd in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x00007ffebab6ebca in c10::detail::torchCheckFail (func=0x7ffecc977968 "validate_outputs", file=0x7ffecc977528 "/workspaces/work/pytorch/torch/csrc/autograd/engine.cpp", line=812, 
    msg="Function SigmoidBackward0 returned an invalid gradient at index 0 - got [80, 1] but expected shape compatible with [<=80, 1]")
    at /workspaces/work/pytorch/c10/util/Exception.cpp:86
#2  0x00007ffec22e746b in torch::autograd::validate_outputs(std::vector<torch::autograd::Edge, std::allocator<torch::autograd::Edge> > const&, std::vector<at::Tensor, std::allocator<at::Tensor> >&, std::function<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > (std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)> const&) (edges=std::vector of length 1, capacity 1 = {...}, grads=std::vector of length 1, capacity 1 = {...}, format_error=...)
    at /workspaces/work/pytorch/torch/csrc/autograd/engine.cpp:812
#3  0x00007ffec22e8569 in torch::autograd::call_function (graph_task=warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::GraphTask, std::allocator<torch::autograd::GraphTask>, (__gnu_cxx::_Lock_policy)2>'
warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::GraphTask, std::allocator<torch::autograd::GraphTask>, (__gnu_cxx::_Lock_policy)2>'
std::shared_ptr<torch::autograd::GraphTask> (use count 3, weak count 2) = {...}, func=0x55555b3c8c80, inputBuffer=...)
    at /workspaces/work/pytorch/torch/csrc/autograd/engine.cpp:910
#4  0x00007ffec22e4b52 in torch::autograd::Engine::evaluate_function (this=0x7ffed24e5410 <torch::autograd::python::PythonEngine::get_python_engine()::engine>, graph_task=warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::GraphTask, std::allocator<torch::autograd::GraphTask>, (__gnu_cxx::_Lock_policy)2>'
warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::GraphTask, std::allocator<torch::autograd::GraphTask>, (__gnu_cxx::_Lock_policy)2>'
 
std::shared_ptr<torch::autograd::GraphTask> (use count 3, weak count 2) = {...}, func=0x55555b3c8c80, inputs=..., cpu_ready_queue=warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
 
std::shared_ptr<torch::autograd::ReadyQueue> (use count 2, weak count 0) = {...}) at /workspaces/work/pytorch/torch/csrc/autograd/engine.cpp:960
#5  0x00007ffec22e4226 in torch::autograd::Engine::thread_main (this=0x7ffed24e5410 <torch::autograd::python::PythonEngine::get_python_engine()::engine>, 
    graph_task=std::shared_ptr<torch::autograd::GraphTask> (empty) = {...}) at /workspaces/work/pytorch/torch/csrc/autograd/engine.cpp:542
#6  0x00007ffec22e2f8e in torch::autograd::Engine::thread_init (this=0x7ffed24e5410 <torch::autograd::python::PythonEngine::get_python_engine()::engine>, device=1, ready_queue=warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
 
std::shared_ptr<torch::autograd::ReadyQueue> (use count 4, weak count 0) = {...}, should_increment=false) at /workspaces/work/pytorch/torch/csrc/autograd/engine.cpp:356
--Type <RET> for more, q to quit, c to continue without paging--
#7  0x00007ffed12c4d23 in torch::autograd::python::PythonEngine::thread_init (this=0x7ffed24e5410 <torch::autograd::python::PythonEngine::get_python_engine()::engine>, device=1, 
    ready_queue=warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
warning: RTTI symbol not found for class 'std::_Sp_counted_ptr_inplace<torch::autograd::ReadyQueue, std::allocator<torch::autograd::ReadyQueue>, (__gnu_cxx::_Lock_policy)2>'
std::shared_ptr<torch::autograd::ReadyQueue> (use count 4, weak count 0) = {...}, should_increment=true)
    at /workspaces/work/pytorch/torch/csrc/autograd/python_engine.cpp:82
#8  0x00007ffec2308619 in std::__invoke_impl<void, void (torch::autograd::Engine::*)(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), torch::autograd::Engine*, signed char, std::shared_ptr<torch::autograd::ReadyQueue>, bool> (__f=@0x55555be0b250: &virtual torch::autograd::Engine::thread_init(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), 
    __t=@0x55555be0b248: 0x7ffed24e5410 <torch::autograd::python::PythonEngine::get_python_engine()::engine>, __args=@0x55555be0b228: true, __args=@0x55555be0b228: true, 
    __args=@0x55555be0b228: true) at /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:73
#9  0x00007ffec2308451 in std::__invoke<void (torch::autograd::Engine::*)(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), torch::autograd::Engine*, signed char, std::shared_ptr<torch::autograd::ReadyQueue>, bool> (__fn=@0x55555be0b250: &virtual torch::autograd::Engine::thread_init(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), 
    __args=@0x55555be0b228: true, __args=@0x55555be0b228: true, __args=@0x55555be0b228: true, __args=@0x55555be0b228: true)
    at /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:95
#10 0x00007ffec23083cd in std::thread::_Invoker<std::tuple<void (torch::autograd::Engine::*)(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), torch::autograd::Engine*, signed char, std::shared_ptr<torch::autograd::ReadyQueue>, bool> >::_M_invoke<0ul, 1ul, 2ul, 3ul, 4ul> (this=0x55555be0b228)
    at /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:244
#11 0x00007ffec2308335 in std::thread::_Invoker<std::tuple<void (torch::autograd::Engine::*)(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), torch::autograd::Engine*, signed char, std::shared_ptr<torch::autograd::ReadyQueue>, bool> >::operator() (this=0x55555be0b228) at /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:253
#12 0x00007ffec2307d79 in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (torch::autograd::Engine::*)(int, std::shared_ptr<torch::autograd::ReadyQueue> const&, bool), torch::autograd::Engine*, signed char, std::shared_ptr<torch::autograd::ReadyQueue>, bool> > >::_M_run (this=0x55555be0b220)
    at /usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/thread:196
#13 0x00007ffff35fcb2f in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#14 0x00007ffff7bdafa3 in start_thread (arg=<optimized out>) at pthread_create.c:486
#15 0x00007ffff797d06f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95