fix native wheel platform tag

pyproject.toml

@@ -13,6 +13,10 @@ classifiers = [
 ]
 dependencies = []
 
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
 [project.optional-dependencies]
 dev = [
   "setuptools",  # for distutils

setup.py

@@ -0,0 +1,11 @@
+from setuptools import Distribution, setup
+
+
+class BinaryDistribution(Distribution):
+  """Mark wheels containing the pre-built Cython modules as platform-specific."""
+
+  def has_ext_modules(self) -> bool:
+    return True
+
+
+setup(distclass=BinaryDistribution)

test.sh

@@ -9,6 +9,17 @@ source ./setup.sh
 # *** build ***
 scons -j8
 
+# Verify the package is installable and is not mislabeled as platform-independent.
+rm -rf dist
+uv build --wheel
+wheel="$(realpath "$(find dist -maxdepth 1 -name '*.whl' -print -quit)")"
+if [[ "$wheel" == *-none-any.whl ]]; then
+  echo "native extension wheel is incorrectly tagged as platform-independent: $wheel" >&2
+  exit 1
+fi
+uv run --isolated --no-project --with "$wheel" --directory / python -c \
+  "import msgq, msgq.visionipc"
+
 # *** lint + test ***
 lefthook run test