Where is `clang-config.cmake` (or `ClangConfig.cmake`)?

Trying to make a derivation for pyside6-addons, but I am stuck with this error:

pyside6-addons> CMake Error at sources/shiboken6/cmake/ShibokenHelpers.cmake:170 (find_package):
pyside6-addons>   Could not find a package configuration file provided by "Clang" with any of
pyside6-addons>   the following names:
pyside6-addons> 
pyside6-addons>     ClangConfig.cmake
pyside6-addons>     clang-config.cmake
pyside6-addons> 
pyside6-addons>   Add the installation prefix of "Clang" to CMAKE_PREFIX_PATH or set
pyside6-addons>   "Clang_DIR" to a directory containing one of the above files.  If "Clang"
pyside6-addons>   provides a separate development package or SDK, be sure it has been
pyside6-addons>   installed.
pyside6-addons> Call Stack (most recent call first):
pyside6-addons>   sources/shiboken6/cmake/ShibokenSetup.cmake:37 (setup_clang)
pyside6-addons>   sources/shiboken6/CMakeLists.txt:13 (include)
pyside6-addons> 
pyside6-addons> 
pyside6-addons> -- Configuring incomplete, errors occurred!
error: builder for '/nix/store/nki55l6f50xjdjnbggwmx30gkca74dn8-python3.12-pyside6-addons-6.7.2.drv' failed with exit code 1;
       last 10 log lines:
       >   Add the installation prefix of "Clang" to CMAKE_PREFIX_PATH or set
       >   "Clang_DIR" to a directory containing one of the above files.  If "Clang"
       >   provides a separate development package or SDK, be sure it has been
       >   installed.
       > Call Stack (most recent call first):
       >   sources/shiboken6/cmake/ShibokenSetup.cmake:37 (setup_clang)
       >   sources/shiboken6/CMakeLists.txt:13 (include)
       >
       > 
       > -- Configuring incomplete, errors occurred!
       For full logs, run 'nix log /nix/store/nki55l6f50xjdjnbggwmx30gkca74dn8-python3.12-pyside6-addons-6.7.2.drv'.

I cannot figure out where is clang-config.cmake (or ClangConfig.cmake)

Here is my work in progress derivation:

{
  lib,
  buildPythonPackage,
  fetchgit,
  setuptools,
  shiboken6,
  cmake,
  qt6,
  llvmPackages
}:

buildPythonPackage {
  pname = "pyside6-addons";
  version = "6.7.2";
  pyproject = true;

  src = fetchgit {
    url = "git://code.qt.io/pyside/pyside-setup.git";
    hash = "sha256-0Ea35j1ij/P/vWIwn/CmQgv0N+J7gH3BXNjdEluguZg=";
  };

  build-system = [ setuptools ];

  dependencies = [
    shiboken6
    qt6.full 
  ];

  nativeBuildInputs = [ cmake llvmPackages.clang ];

  meta = {
    description = "Python bindings for the Qt cross-platform application and UI framework";
    homepage = "https://wiki.qt.io/Qt_for_Python";
    license = with lib.licenses; [
     asl20
     bsd3
     gpl2Only
     gpl3Only
   ];
  };
}

I recommend searching through nixpkgs for examples.

$ nix-locate ClangConfig.cmake mentions mainly llvmPackages_XX.clang