Add debug output for CMAKE_PREFIX_PATH and simplify cibuildwheel workflow

- Add debug echo for CMAKE_PREFIX_PATH in macOS before-build
- Remove workflow-level CIBW_ENVIRONMENT overrides, rely on pyproject.toml
- The {project} placeholder in pyproject.toml should be expanded by cibuildwheel

Author: jeongseok-meta

.github/workflows/cibuildwheel.yml

@@ -58,11 +58,7 @@ jobs:
       - name: Build wheels
         uses: pypa/cibuildwheel@v2.22.0
         # Configuration is in pyproject.toml (generated from pyproject-pypi.toml.j2)
-        env:
-          # Override environment for macOS/Windows to use cibuildwheel's {project} placeholder
-          # {project} expands to the project directory path at build time
-          CIBW_ENVIRONMENT_MACOS: "CMAKE_PREFIX_PATH={project}/.pixi/envs/default MOMENTUM_BUILD_WITH_FBXSDK=OFF"
-          CIBW_ENVIRONMENT_WINDOWS: "CMAKE_PREFIX_PATH={project}/.pixi/envs/default MOMENTUM_BUILD_WITH_FBXSDK=OFF"
+        # CMAKE_PREFIX_PATH is set via environment in pyproject.toml using {project} placeholder
 
       - uses: actions/upload-artifact@v4
         with:

pyproject-pypi.toml.j2

@@ -260,6 +260,9 @@ build-frontend = "pip; args: --no-build-isolation"
 before-build = """
 pip install scikit-build-core pybind11 setuptools-scm
 pip install "torch>=2.8.0,<2.9" --index-url https://download.pytorch.org/whl/cpu
+# Set CMAKE_PREFIX_PATH explicitly
+export CMAKE_PREFIX_PATH="{project}/.pixi/envs/default"
+echo "CMAKE_PREFIX_PATH=$CMAKE_PREFIX_PATH"
 """
 environment = { CMAKE_PREFIX_PATH = "{project}/.pixi/envs/default", MOMENTUM_BUILD_WITH_FBXSDK = "OFF" }