I got this stack trace today.
#0  0x00007ffff7803f47 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff78058b1 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff784e907 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#3  0x00007ffff785597a in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#4  0x00007ffff785cef4 in free () from /lib/x86_64-linux-gnu/libc.so.6
#5  0x00007fff5506a425 in __gnu_cxx::new_allocator<int>::deallocate (this=0x7fffffffcfd0, __p=<optimized out>)
    at /usr/include/c++/7/ext/new_allocator.h:125
#6  std::allocator_traits<std::allocator<int> >::deallocate (__a=..., __n=<optimized out>, __p=<optimized out>)
    at /usr/include/c++/7/bits/alloc_traits.h:462
#7  std::_Vector_base<int, std::allocator<int> >::_M_deallocate (this=0x7fffffffcfd0, __n=<optimized out>, __p=<optimized out>)
    at /usr/include/c++/7/bits/stl_vector.h:180
#8  std::_Vector_base<int, std::allocator<int> >::~_Vector_base (this=0x7fffffffcfd0, __in_chrg=<optimized out>)
    at /usr/include/c++/7/bits/stl_vector.h:162
#9  std::vector<int, std::allocator<int> >::~vector (this=0x7fffffffcfd0, __in_chrg=<optimized out>) at /usr/include/c++/7/bits/stl_vector.h:435
#10 extract_spans (span_scores=..., candidate_starts=..., candidate_ends=..., num_output_spans=..., max_sentence_length=<optimized out>,
    _sort_spans=<optimized out>, _suppress_crossing=<optimized out>) at span_prune.cpp:75
#11 0x00007fff5507c0c6 in pybind11::detail::argument_loader<at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool>::call_impl<at::Tensor, at::Tensor (*&)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool), 0ul, 1ul, 2ul, 3ul, 4ul, 5ul, 6ul, pybind11::detail::void_type> (
    f=<optimized out>, this=0x7fffffffd460)
    at /mnt/data2/hussein/miniconda3/envs/torch-sci/lib/python3.7/site-packages/torch/include/pybind11/cast.h:1931
#12 pybind11::detail::argument_loader<at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool>::call<at::Tensor, pybind11::detail::void_type, at::Tensor (*&)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool)>(at::Tensor (*&)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool)) && (f=<optimized out>, this=<optimized out>)
    at /mnt/data2/hussein/miniconda3/envs/torch-sci/lib/python3.7/site-packages/torch/include/pybind11/cast.h:1908
#13 pybind11::cpp_function::initialize<at::Tensor (*&)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool), at::Tensor, at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool, pybind11::name, pybind11::scope, pybind11::sibling, char [14]>(at::Tensor (*&)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool), at::Tensor (*)(at::Tensor, at::Tensor, at::Tensor, at::Tensor, int, bool, bool), pybind11::name const&, pybind11::scope const&, pybind11::sibling const&, char const (&) [14])::{lambda(pybind11::detail::function_call&)#3}::operator()(pybind11::detail::function_call&) const (__closure=<optimized out>, call=...)
    at /mnt/data2/hussein/miniconda3/envs/torch-sci/lib/python3.7/site-packages/torch/include/pybind11/pybind11.h:155
#14 0x00007fff55078690 in pybind11::cpp_function::dispatcher (self=<optimized out>, args_in=0x7ffec673e4b0, kwargs_in=0x0)
    at /mnt/data2/hussein/miniconda3/envs/torch-sci/lib/python3.7/site-packages/torch/include/pybind11/pybind11.h:620
#15 0x00005555556b9c94 in _PyMethodDef_RawFastCallKeywords (method=0x5555574dfb40, self=0x7ffff5f24750, args=0x555625428c58,
    nargs=<optimized out>, kwnames=<optimized out>) at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:694
#16 0x00005555556b9db1 in _PyCFunction_FastCallKeywords (func=0x7fff5511ebe0, args=<optimized out>, nargs=<optimized out>, kwnames=<optimized out>)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:734
#17 0x00005555557255be in call_function (kwnames=0x0, oparg=7, pp_stack=<synthetic pointer>)
    at /tmp/build/80754af9/python_1588882889832/work/Python/ceval.c:4568
#18 _PyEval_EvalFrameDefault (f=<optimized out>, throwflag=<optimized out>) at /tmp/build/80754af9/python_1588882889832/work/Python/ceval.c:3093
#19 0x000055555566a31b in function_code_fastcall (globals=<optimized out>, nargs=2, args=<optimized out>, co=0x7ffef5921a50)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:283
#20 _PyFunction_FastCallDict (func=<optimized out>, args=0x7fffffffd960, nargs=2, kwargs=<optimized out>)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:322
#21 0x0000555555688b93 in _PyObject_Call_Prepend (callable=0x7ffef5928320, obj=<optimized out>, args=0x7ffec68de050, kwargs=0x7ffec6a20410)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:908
#22 0x000055555567b95e in PyObject_Call (callable=0x7ffec6abbaa0, args=<optimized out>, kwargs=<optimized out>)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:245
#23 0x000055555572251a in do_call_core (kwdict=0x7ffec6a20410, callargs=0x7ffec68de050, func=0x7ffec6abbaa0)
    at /tmp/build/80754af9/python_1588882889832/work/Python/ceval.c:4645
#24 _PyEval_EvalFrameDefault (f=<optimized out>, throwflag=<optimized out>) at /tmp/build/80754af9/python_1588882889832/work/Python/ceval.c:3191
#25 0x00005555556692b9 in _PyEval_EvalCodeWithName (_co=0x7fff556e6030, globals=<optimized out>, locals=<optimized out>, args=<optimized out>,
    argcount=<optimized out>, kwnames=0x0, kwargs=0x0, kwcount=<optimized out>, kwstep=2, defs=0x0, defcount=0, kwdefs=0x0, closure=0x0,
    name=0x7ffff6c651b0, qualname=0x7fff556e5230) at /tmp/build/80754af9/python_1588882889832/work/Python/ceval.c:3930
#26 0x000055555566a3e5 in _PyFunction_FastCallDict (func=<optimized out>, args=0x7fffffffdcc0, nargs=2, kwargs=<optimized out>)
    at /tmp/build/80754af9/python_1588882889832/work/Objects/call.c:376

Any idea what is going on here?