Bug 2250848

gnucash fails to build with Python 3.13.0a1.

/builddir/build/BUILD/gnucash-5.4/gnucash/python/gncmod-python.c: In function ‘libgncmod_python_gnc_module_init’:
/builddir/build/BUILD/gnucash-5.4/gnucash/python/gncmod-python.c:71:5: error: implicit declaration of function ‘PySys_SetArgv’ [-Werror=implicit-function-declaration]
   71 |     PySys_SetArgv(0, &argv);
      |     ^~~~~~~~~~~~~
cc1: all warnings being treated as errors

According to https://docs.python.org/3.13/whatsnew/3.13.html:
Remove the following old functions to configure the Python initialization, deprecated in Python 3.11:
    PySys_AddWarnOptionUnicode(): use PyConfig.warnoptions instead.
    PySys_AddWarnOption(): use PyConfig.warnoptions instead.
    PySys_AddXOption(): use PyConfig.xoptions instead.
    PySys_HasWarnOptions(): use PyConfig.xoptions instead.
    PySys_SetArgvEx(): set PyConfig.argv instead.
    PySys_SetArgv(): set PyConfig.argv instead.
    PySys_SetPath(): set PyConfig.module_search_paths instead.
    Py_SetPath(): set PyConfig.module_search_paths instead.
    Py_SetProgramName(): set PyConfig.program_name instead.
    Py_SetPythonHome(): set PyConfig.home instead.
    Py_SetStandardStreamEncoding(): set PyConfig.stdio_encoding instead, and set also maybe PyConfig.legacy_windows_stdio (on Windows).
    _Py_SetProgramFullPath(): set PyConfig.executable instead.


https://docs.python.org/3.13/whatsnew/3.13.html

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.13/fedora-rawhide-x86_64/06660785-gnucash/

For all our attempts to build gnucash with Python 3.13, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.13/package/gnucash/

Testing and mass rebuild of packages is happening in copr.
You can follow these instructions to test locally in mock if your package builds with Python 3.13:
https://copr.fedorainfracloud.org/coprs/g/python/python3.13/

Let us know here if you have any questions.

Python 3.13 is planned to be included in Fedora 41.
To make that update smoother, we're building Fedora packages with all pre-releases of Python 3.13.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires),
so if this package is required a lot, it's important for us to get it fixed soon.

We'd appreciate help from the people who know this package best,
but if you don't want to work on this now, let us know so we can try to work around it on our side.