Add args param to build-frontend option

test/test_build_frontend_args.py

@@ -0,0 +1,34 @@
+import subprocess
+
+import pytest
+
+from . import utils
+from .test_projects.c import new_c_project
+
+
+@pytest.mark.parametrize("frontend_name", ["pip", "build"])
+def test_build_frontend_args(tmp_path, capfd, frontend_name):
+    project = new_c_project()
+    project_dir = tmp_path / "project"
+    project.generate(project_dir)
+
+    # the build will fail because the frontend is called with '-h' - it prints the help message
+    with pytest.raises(subprocess.CalledProcessError):
+        utils.cibuildwheel_run(
+            project_dir,
+            add_env={
+                "CIBW_BUILD": "cp311-*",
+                "CIBW_BUILD_FRONTEND": f"{frontend_name}; args: -h",
+            },
+        )
+
+    captured = capfd.readouterr()
+    print(captured.out)
+
+    # check that the help message was printed
+    if frontend_name == "pip":
+        assert "Usage:" in captured.out
+        assert "Wheel Options:" in captured.out
+    else:
+        assert "usage:" in captured.out
+        assert "A simple, correct Python build frontend." in captured.out