windows arm free-threading fails to find Python Development.Module

[minrk]

It's unclear to me if this is a cibuildwheel issue, a cmake issue, or a scikit-build issue (or something else!), but when I try to build wheels for lots of platforms, except free-threading builds for Windows ARM.

The real project I'm working on is pyzmq, but I set up a sample repo building the skbuild C example on a few platforms and it's the same. Everything works except Windows arm free-threading builds, which fail at FindPython with:

python -m build 'C:\a\test-skbuild-win-arm\test-skbuild-win-arm' --wheel '--outdir=C:\Users\runneradmin\AppData\Local\Temp\cibw-run-5cs_5kcr\cp313t-win_arm64\built_wheel'
  * Creating isolated environment: venv+pip...
  * Installing packages in isolated environment:
    - scikit-build-core
  * Getting build dependencies for wheel...
  * Building wheel...
  *** scikit-build-core 0.11.5 using CMake 3.31.6 (wheel)
  *** Configuring CMake...
  loading initial cache file C:\Users\RUNNER~1\AppData\Local\Temp\tmpvks6pqs2\build\CMakeInit.txt
  -- Building for: Visual Studio 17 2022
  -- The C compiler identification is MSVC 19.44.35213.0
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - done
  -- Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.44.35207/bin/Hostx64/arm64/cl.exe - skipped
  -- Detecting C compile features
  -- Detecting C compile features - done
  CMake Error at C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:233 (message):
    Could NOT find Python (missing: Development.Module) (found version
    "3.13.5")
  Call Stack (most recent call first):
    C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:603 (_FPHSA_FAILURE_MESSAGE)
    C:/Program Files/CMake/share/cmake-3.31/Modules/FindPython.cmake:673 (find_package_handle_standard_args)
    CMakeLists.txt:4 (find_package)
  
  
  -- Configuring incomplete, errors occurred!
  
  *** CMake configuration failed

Any tips on how to further debug? It's only 314t and 313t builds targeting windows arm from x64 that do this.