NVIDIA NVCC ICE-1

• branch: https://github.com/crtrott/mdspan/tree/cuda-ICE-1
• SHA: f083b6dfefe2
• cmake command:
  cmake -DMDSPAN_ENABLE_TESTS=ON -DMDSPAN_ENABLE_CUDA=ON -DMDSPAN_CXX_STANDARD=17 -DCMAKE_CXX_STANDARD=17 -DCMAKE_CUDA_FLAGS="--expt-relaxed-constexpr" ../
• Version: cmake 3.21.1, GCC 9.2.0, NVCC 11.1, 11.4[from nvhpc] (didn't test others yet)

Error 11.1:

 make
[  5%] Building CXX object tests/googletest-build/googletest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
[ 10%] Linking CXX static library ../../../lib/libgtest.a
[ 10%] Built target gtest
[ 15%] Building CXX object tests/googletest-build/googletest/CMakeFiles/gtest_main.dir/src/gtest_main.cc.o
[ 20%] Linking CXX static library ../../../lib/libgtest_main.a
[ 20%] Built target gtest_main
[ 25%] Building CUDA object tests/CMakeFiles/test_mdspan_conversion.dir/test_mdspan_conversion.cpp.o
/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/default_accessor.hpp(61): warning: __host__ annotation is ignored on a function("default_accessor") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/default_accessor.hpp(61): warning: __device__ annotation is ignored on a function("default_accessor") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/standard_layout_static_array.hpp(542): warning: __host__ annotation is ignored on a function("__partially_static_sizes_tagged") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/standard_layout_static_array.hpp(542): warning: __device__ annotation is ignored on a function("__partially_static_sizes_tagged") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/compressed_pair.hpp(59): error: Internal Compiler Error (codegen): "internal error during structure layout!"

make[2]: *** [tests/CMakeFiles/test_mdspan_conversion.dir/test_mdspan_conversion.cpp.o] Error 2
make[1]: *** [tests/CMakeFiles/test_mdspan_conversion.dir/all] Error 2
make: *** [all] Error 2

Error 11.4:

[ 25%] Building CUDA object tests/CMakeFiles/test_mdspan_conversion.dir/test_mdspan_conversion.cpp.o
/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/default_accessor.hpp(61): warning: __host__ annotation is ignored on a function("default_accessor") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/default_accessor.hpp(61): warning: __device__ annotation is ignored on a function("default_accessor") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/standard_layout_static_array.hpp(542): warning: __host__ annotation is ignored on a function("__partially_static_sizes_tagged") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/standard_layout_static_array.hpp(542): warning: __device__ annotation is ignored on a function("__partially_static_sizes_tagged") that is explicitly defaulted on its first declaration

/ascldap/users/crtrott/Kokkos/mdspan/include/experimental/__p0009_bits/compressed_pair.hpp(59): error: Internal Compiler Error (codegen): "internal error during structure layout!"

make[2]: *** [tests/CMakeFiles/test_mdspan_conversion.dir/test_mdspan_conversion.cpp.o] Error 2
make[1]: *** [tests/CMakeFiles/test_mdspan_conversion.dir/all] Error 2

Reproduce the failure with the listed CMake command and NVCC 11.1 or 11.4, focusing first on tests/test_mdspan_conversion.cpp and the diagnostic at include/experimental/__p0009_bits/compressed_pair.hpp:59. Compare the compiler behavior and determine what change, if any, makes the CUDA test build complete without the internal compiler error.