I have a C++ code that generates a python expansion, through setuptools.Extension.
In the setup.py file , I define a build_ext, and relies upon CMake to build the extension :

class BuildCMakeExtension(build_ext.build_ext):
  """Our custom build_ext command.

  Uses CMake to build extensions instead of a bare compiler (e.g. gcc, clang).
  """

  def run(self):
    self._check_build_environment()
    for ext in self.extensions:
      self.build_extension(ext)

  def _check_build_environment(self):
    ...

  def build_extension(self, ext):
    extension_dir = os.path.abspath(
        os.path.dirname(self.get_ext_fullpath(ext.name)))
    build_cfg = 'Debug' if self.debug else 'Release'
    cmake_args = [
        ...
    ]
    if platform.system() != 'Windows':
      cmake_args.extend([
          f'-DPython3_LIBRARY={sysconfig.get_paths()["stdlib"]}',
          f'-DPython3_INCLUDE_DIR={sysconfig.get_paths()["include"]}',
      ])
    if platform.system() == 'Darwin' and os.environ.get('ARCHFLAGS'):
      osx_archs = []
      if '-arch x86_64' in os.environ['ARCHFLAGS']:
        osx_archs.append('x86_64')
      if '-arch arm64' in os.environ['ARCHFLAGS']:
        osx_archs.append('arm64')
      cmake_args.append(f'-DCMAKE_OSX_ARCHITECTURES={";".join(osx_archs)}')
    os.makedirs(self.build_temp, exist_ok=True)
    subprocess.check_call(
        ['cmake', ext.source_dir] + cmake_args, cwd=self.build_temp)
    subprocess.check_call(
        ['cmake', '--build', '.', f'-j{os.cpu_count()}', '--config', build_cfg],
        cwd=self.build_temp)

    # Force output to <extension_dir>/. Amends CMake multigenerator output paths
    # on Windows and avoids Debug/ and Release/ subdirs, which is CMake default.
    ct_dir = os.path.join(extension_dir, 'cytosim')  # pylint:disable=unreachable
    for cfg in ('Release', 'Debug'):
      cfg_dir = os.path.join(extension_dir, cfg)
      if os.path.isdir(cfg_dir):
        for f in os.listdir(cfg_dir):
          shutil.move(os.path.join(cfg_dir, f), ct_dir)

In the CMakeLists of the project, I add the module through pybind11_add_module(cytosim ${PYCY_SOURCES}) and set_target_properties(cytosim PROPERTIES OUTPUT_NAME "${PY_LIBRARY_NAME}")

This works well somehow (no idea how tbh) and I happily find my cytosim.xxxxx.so file in the right place site_packages/cytosim once the build is done.

However, the compilation also creates an executable, via add_executable(${SIM_TARGET} "${PROJECT_SOURCE_DIR}/../src/sim/sim.cc") ; however it does not go in site_packages.

How can I do to get it there ?