[BUG]: Cross compilation (x86_64-linux -> armv7l) fails with LONG_BIT related errors

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What version (or hash if on master) of pybind11 are you using?

3.0.1

Problem description

I get these errors:

*** Building project with Ninja...
[0/2] Re-checking globbed directories...
[3/108] Building CXX object tests/test_cross_module_rtti/CMakeFiles/test_cross_module_rtti_bindings.dir/bindings.cpp.o
FAILED: [code=1] tests/test_cross_module_rtti/CMakeFiles/test_cross_module_rtti_bindings.dir/bindings.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -Dtest_cross_module_rtti_bindings_EXPORTS -I/build/source/include -I/build/source/build/tests/test_cross_module_rtti -I/build/source/tests/test_cross_module_rtti -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/test_cross_module_rtti/CMakeFiles/test_cross_module_rtti_bindings.dir/bindings.cpp.o -MF tests/test_cross_module_rtti/CMakeFiles/test_cross_module_rtti_bindings.dir/bindings.cpp.o.d -o tests/test_cross_module_rtti/CMakeFiles/test_cross_module_rtti_bindings.dir/bindings.cpp.o -c /build/source/tests/test_cross_module_rtti/bindings.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/tests/test_cross_module_rtti/bindings.cpp:1:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[4/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/pybind11_tests.cpp.o -c /build/source/tests/pybind11_tests.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/eval.h:14,
                 from /build/source/tests/pybind11_tests.h:3,
                 from /build/source/tests/pybind11_tests.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[5/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_async.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_async.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_async.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_async.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_async.cpp.o -c /build/source/tests/test_async.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/eval.h:14,
                 from /build/source/tests/pybind11_tests.h:3,
                 from /build/source/tests/test_async.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[6/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_call_policies.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_call_policies.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_call_policies.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_call_policies.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_call_policies.cpp.o -c /build/source/tests/test_call_policies.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/eval.h:14,
                 from /build/source/tests/pybind11_tests.h:3,
                 from /build/source/tests/test_call_policies.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[7/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_chrono.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_chrono.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_chrono.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_chrono.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_chrono.cpp.o -c /build/source/tests/test_chrono.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/chrono.h:13,
                 from /build/source/tests/test_chrono.cpp:11:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[8/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_callbacks.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_callbacks.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_callbacks.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_callbacks.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_callbacks.cpp.o -c /build/source/tests/test_callbacks.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/functional.h:12,
                 from /build/source/tests/test_callbacks.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[9/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_class_release_gil_before_calling_cpp_dtor.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_class_release_gil_before_calling_cpp_dtor.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_class_release_gil_before_calling_cpp_dtor.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_class_release_gil_before_calling_cpp_dtor.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_class_release_gil_before_calling_cpp_dtor.cpp.o -c /build/source/tests/test_class_release_gil_before_calling_cpp_dtor.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/tests/test_class_release_gil_before_calling_cpp_dtor.cpp:1:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[10/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_builtin_casters.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_builtin_casters.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_builtin_casters.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_builtin_casters.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_builtin_casters.cpp.o -c /build/source/tests/test_builtin_casters.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/complex.h:12,
                 from /build/source/tests/test_builtin_casters.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[11/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_buffers.cpp.o -c /build/source/tests/test_buffers.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/complex.h:12,
                 from /build/source/tests/test_buffers.cpp:10:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
[12/108] Building CXX object tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o
FAILED: [code=1] tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o 
/nix/store/br8a01761nsa7kpr42i6dd9sdmk78xi1-armv7l-unknown-linux-gnueabihf-gcc-wrapper-14.3.0/bin/armv7l-unknown-linux-gnueabihf-g++ -DPYBIND11_TEST_BOOST -DPYBIND11_TEST_EIGEN -Dpybind11_tests_EXPORTS -I/build/source/include -isystem /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13 -isystem /nix/store/m20sxgg1xyxjwy5df9b1gajwspzhjpzz-eigen-armv7l-unknown-linux-gnueabihf-3.4.1/include/eigen3 -O3 -DNDEBUG -fPIC -fvisibility=hidden -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated -Wundef -Wnon-virtual-dtor -flto=auto -fno-fat-lto-objects -MD -MT tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o -MF tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o.d -o tests/CMakeFiles/pybind11_tests.dir/test_class.cpp.o -c /build/source/tests/test_class.cpp
In file included from /nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/Python.h:64,
                 from /build/source/include/pybind11/conduit/wrap_include_python_h.h:44,
                 from /build/source/include/pybind11/detail/common.h:12,
                 from /build/source/include/pybind11/attr.h:13,
                 from /build/source/include/pybind11/detail/class.h:12,
                 from /build/source/include/pybind11/pybind11.h:12,
                 from /build/source/include/pybind11/stl.h:12,
                 from /build/source/tests/test_class.cpp:17:
/nix/store/3lll9y925zz9393sa59h653xik66srjb-python3-3.13.9/include/python3.13/pyport.h:399:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
  399 | #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
      |  ^~~~~
ninja: build stopped: subcommand failed.

*** CMake build failed

Reproducible example code

With a basic installation of Nix, you can reproduce the error with:

nix build -L nixpkgs#pkgsCross.armv7l-hf-multiplatform.python3.pkgs.pybind11

Is this a regression? Put the last known working version here if it is.

I remember I managed to cross compile pybind11 2.x a few months ago.

Start by reproducing the armv7l cross-compilation failure in tests/test_cross_module_rtti/bindings.cpp or tests/pybind11_tests.cpp, using the shown Python 3.13 headers and generated build command. Inspect the interaction between the cross compiler, Python.h, and pyport.h's LONG_BIT check. Done means the affected test sources compile successfully for x86_64-linux to armv7l.