Install build dependencies in before-build and pass --no-build-isolation

Author: lysnikolaou

.github/workflows/wheels.yml

@@ -142,6 +142,13 @@ jobs:
         shell: bash -el {0}
         run: echo "sdist_name=$(cd ./dist && ls -d */)" >> "$GITHUB_ENV"
 
+      # TODO: Remove this and installing build deps in cibw_before_build.sh
+      # after NumPy can be built with a released Cython
+      - name: Define CIBW_BUILD_FRONTEND environment variable
+        if: ${{ matrix.python[0] == 'cp313t' }}
+        run: |
+          echo "CIBW_BUILD_FRONTEND='pip; args: --no-build-isolation'" >> "$GITHUB_ENV"
+
       - name: Build wheels
         uses: pypa/[email protected]
         with:

pyproject.toml

@@ -159,6 +159,12 @@ test-command = """
 before-build = "pip install delvewheel"
 repair-wheel-command = "delvewheel repair -w {dest_dir} {wheel}"
 
+[tool.cibuildwheel.linux]
+before-build = "bash {project}/scripts/cibw_before_build.sh"
+
+[tool.cibuildwheel.macos]
+before-build = "bash {project}/scripts/cibw_before_build.sh"
+
 [[tool.cibuildwheel.overrides]]
 select = "*-musllinux*"
 before-test = "apk update && apk add musl-locales"

scripts/cibw_before_build.sh

@@ -0,0 +1,9 @@
+# TODO: delete along with enabling build isolation by unsetting
+# CIBW_BUILD_FRONTEND when scipy is buildable under free-threaded
+# python with a released version of cython
+FREE_THREADED_BUILD="$(python -c "import sysconfig; print(bool(sysconfig.get_config_var('Py_GIL_DISABLED')))")"
+if [[ $FREE_THREADED_BUILD == "True" ]]; then
+    python -m pip install -U pip
+    python -m pip install -i https://pypi.anaconda.org/scientific-python-nightly-wheels/simple numpy cython
+    python -m pip install ninja meson-python
+fi