fix: fetch data directories before CI tests

.github/workflows/validate.yml

@@ -142,6 +142,14 @@ jobs:
         continue-on-error: true
         run: python scripts/export_native.py --all --fetch --output-dir "$RUNNER_TEMP/native"
 
+      # A pack built without its data directories exits non-zero: it is not
+      # the pack a user gets. Tests that build packs need the same trees a
+      # release build has, as deploy-site.yml fetches them.
+      - name: Fetch the data directories
+        run: python scripts/refresh_data_dirs.py
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Run test suite
         # No test downloads a release asset: 252 MB files fetched into the
         # shared cache filled the runner's disk and changed what later tests

tests/test_audit_regressions.py

@@ -3514,5 +3514,20 @@ class TheIssueFormListsEveryPlatform(unittest.TestCase):
             self.assertIn(display, options)
 
 
+
+class TheTestJobHasTheDataTrees(unittest.TestCase):
+    """Packs built without data directories exit non-zero; the CI test job
+    had none, and two pack parity tests failed there only."""
+
+    def test_the_trees_are_fetched_before_the_suite(self):
+        steps = yaml.safe_load(
+            (ROOT / ".github" / "workflows" / "validate.yml").read_text()
+        )["jobs"]["run-tests"]["steps"]
+        runs = [step.get("run", "") for step in steps]
+        fetch = next(i for i, run in enumerate(runs) if "refresh_data_dirs.py" in run)
+        suite = next(i for i, run in enumerate(runs) if "unittest discover" in run)
+        self.assertLess(fetch, suite)
+
+
 if __name__ == "__main__":
     unittest.main()