python 3.12 build failure on macOS Sonoma

[externl]

❯ make PYTHON=(brew --prefix [email protected])/bin/python3.12
Compiling [macosx-shared] ../cpp/src/Slice/Grammar.cpp
Compiling [macosx-shared] ../cpp/src/Slice/MD5.cpp
Compiling [macosx-shared] ../cpp/src/Slice/FileTracker.cpp
Compiling [macosx-shared] ../cpp/src/Slice/MD5I.cpp
Compiling [macosx-shared] ../cpp/src/Slice/Checksum.cpp
Compiling [macosx-shared] ../cpp/src/Slice/Parser.cpp
Compiling [macosx-shared] ../cpp/src/Slice/Preprocessor.cpp
Compiling [macosx-shared] ../cpp/src/Slice/SliceUtil.cpp
Compiling [macosx-shared] ../cpp/src/Slice/Python.cpp
Compiling [macosx-shared] ../cpp/src/Slice/Scanner.cpp
Compiling [macosx-shared] ../cpp/src/Slice/PythonUtil.cpp
Compiling [macosx-shared] ../cpp/src/Slice/StringLiteralUtil.cpp
Compiling [macosx-shared] modules/IcePy/BatchRequestInterceptor.cpp
Compiling [macosx-shared] modules/IcePy/Communicator.cpp
Compiling [macosx-shared] modules/IcePy/Connection.cpp
Compiling [macosx-shared] modules/IcePy/ConnectionInfo.cpp
Compiling [macosx-shared] modules/IcePy/Current.cpp
Compiling [macosx-shared] modules/IcePy/Dispatcher.cpp
Compiling [macosx-shared] modules/IcePy/Endpoint.cpp
Compiling [macosx-shared] modules/IcePy/EndpointInfo.cpp
Compiling [macosx-shared] modules/IcePy/ImplicitContext.cpp
Compiling [macosx-shared] modules/IcePy/Init.cpp
Compiling [macosx-shared] modules/IcePy/Logger.cpp
Compiling [macosx-shared] modules/IcePy/ObjectAdapter.cpp
Compiling [macosx-shared] modules/IcePy/Operation.cpp
Compiling [macosx-shared] modules/IcePy/Properties.cpp
Compiling [macosx-shared] modules/IcePy/Proxy.cpp
Compiling [macosx-shared] modules/IcePy/PropertiesAdmin.cpp
Compiling [macosx-shared] modules/IcePy/Slice.cpp
Compiling [macosx-shared] modules/IcePy/Thread.cpp
Compiling [macosx-shared] modules/IcePy/Types.cpp
Compiling [macosx-shared] modules/IcePy/Util.cpp
Compiling [macosx-shared] modules/IcePy/ValueFactoryManager.cpp
modules/IcePy/Types.cpp:4627:5: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
    1, &UnsetType
    ^
    {}
1 error generated.
make: *** [modules/IcePy/build/macosx/shared/pic/Types.o] Error 1
make: *** Waiting for unfinished jobs....

[externl]

I looks like the PyObject (which is a typedef of _object) struct changed between 3.11 and 3.12

3.11

struct _object {
    _PyObject_HEAD_EXTRA
    Py_ssize_t ob_refcnt;
    PyTypeObject *ob_type;
};

3.12

struct _object {
    _PyObject_HEAD_EXTRA

#if (defined(__GNUC__) || defined(__clang__)) \
        && !(defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L)
    // On C99 and older, anonymous union is a GCC and clang extension
    __extension__
#endif
#ifdef _MSC_VER
    // Ignore MSC warning C4201: "nonstandard extension used:
    // nameless struct/union"
    __pragma(warning(push))
    __pragma(warning(disable: 4201))
#endif
    union {
       Py_ssize_t ob_refcnt;
#if SIZEOF_VOID_P > 4
       PY_UINT32_T ob_refcnt_split[2];
#endif
    };
#ifdef _MSC_VER
    __pragma(warning(pop))
#endif

    PyTypeObject *ob_type;
};

We're defining

//
PyObject UnsetValue =
{
    _PyObject_EXTRA_INIT
    1, &UnsetType
};

I wonder if we should be using PyObject_HEAD_INIT instead of manually doing it ourselves. Just need to ensure it's available everywhere.

[externl]

This was fixed in 4fa13cd