Fix sdist to include c++ files and check build with sdist. (#177)

.github/workflows/tests.yml

@@ -86,6 +86,10 @@ jobs:
         run: python -m build --sdist .
       - name: Check the sdist
         run: python -m twine check dist/*.tar.gz
+      - name: Check sdist build
+        run: |
+          python -m pip install dist/*.tar.gz
+          python -c "import george"
       - uses: actions/upload-artifact@v4
         with:
           name: sdist

pyproject.toml

@@ -15,7 +15,11 @@ build-backend = "scikit_build_core.build"
 
 [tool.scikit-build]
 metadata.version.provider = "scikit_build_core.metadata.setuptools_scm"
-sdist.include = ["src/george/george_version.py"]
+sdist.include = [
+    "src/george/george_version.py",
+    "src/george/kernel_interface.cpp",
+    "src/george/solvers/_hodlr.cpp",
+]
 wheel.install-dir = "george"
 minimum-version = "0.5"
 build-dir = "build/{wheel_tag}"