[BUG]: uv sync is broken on Windows

[lassefschmidt]

Description

calling uv sync --all-extras on my system (develop branch) fails. let me know if you need more information.

Code for Reproduction

uv sync --all-extras

Exception Message

Resolved 196 packages in 1ms
  × Failed to build `openimageio==3.0.11.0`
  ├─▶ The build backend returned an error                                                                                                                                                                                                                                                                
  ╰─▶ Call to `scikit_build_core.build.build_wheel` failed (exit code: 1)

      [stdout]
      *** scikit-build-core 0.11.6 using CMake 4.2.0 (wheel)
      *** Configuring CMake...
      loading initial cache file C:\Users\lasse\AppData\Local\Temp\tmpoppumm5t\build\CMakeInit.txt
      -- Building for: NMake Makefiles
      -- Configuring incomplete, errors occurred!

      [stderr]
      CMake Error at CMakeLists.txt:15 (project):
        Running

         'nmake' '-?'

        failed with:

         no such file or directory


      CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
      CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage

      *** CMake configuration failed

      hint: This usually indicates a problem with the package or the build environment.
  help: `openimageio` (v3.0.11.0) was included because `colour-science[optional]` (v0.4.6) depends on `openimageio`

Environment Information

not possible as colour cannot be installed

[KelSolaar]

It is odd that it is trying to build, can you tell me which Python version is this building the venv against? Our CI works for 3.11 -> 3.14, I also tested at work and everything seems allright!

[lassefschmidt]

this works, and does not try to build !
uv sync --all-extras --python 3.13.7

this works as well
uv sync --all-extras --python 3.11.14

but this tries to build and fails
uv sync --all-extras --python 3.14.0

(all using the most recent develop branch, ca6e64c)

[KelSolaar]

Which version of OIIO is it trying to build? Looking at latest CI, e.g., https://github.com/colour-science/colour/actions/runs/19985360933/job/57334946102, it builds with openimageio==3.1.8.0 which is the latest but your OP shows 3.0.11.0 which is over 2 months old: https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.11.0

[lassefschmidt]

This is the new error message using ca6e64c.

uv sync --all-extras --python 3.14.0

Using CPython 3.14.0
Removed virtual environment at: .venv
Creating virtual environment at: .venv
Resolved 196 packages in 1ms
  × Failed to build `openimageio==3.0.11.0`
  ├─▶ The build backend returned an error
  ╰─▶ Call to `scikit_build_core.build.build_wheel` failed (exit code: 1)

      [stdout]
      *** scikit-build-core 0.11.6 using CMake 4.2.0 (wheel)
      *** Configuring CMake...
      loading initial cache file C:\Users\lasse\AppData\Local\Temp\tmps611bro1\build\CMakeInit.txt
      -- Building for: NMake Makefiles
      -- Configuring incomplete, errors occurred!

      [stderr]
      CMake Error at CMakeLists.txt:15 (project):
        Running

         'nmake' '-?'

        failed with:

         no such file or directory


      CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
      CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage

      *** CMake configuration failed

      hint: This usually indicates a problem with the package or the build environment.
  help: `openimageio` (v3.0.11.0) was included because `colour-science[optional]` (v0.4.7) depends on `openimageio`

v0.4.7 seems to try and build openimageio==3.0.11.0

[KelSolaar]

Super odd! You should be able to add --with openimageio==3.1.8.0 to the command line for now if you need Python 3.14 on your machine. I will check which version is being picked up on work machine.