fix: fail --verify-packs when no pack was checked

scripts/generate_pack.py

@@ -2497,8 +2497,10 @@ def _run_verify_packs(args: argparse.Namespace) -> None:
         set(os.listdir(args.output_dir)) if os.path.isdir(args.output_dir) else set()
     )
 
+    verified = 0
     for platform_name in platforms:
         found = sorted(expected[platform_name] & on_disk)
+        verified += len(found)
         if not found:
             # Naming a platform is asking about its pack: FAIL, with the
             # command that builds it. With --all, a platform whose pack was
@@ -2545,6 +2547,11 @@ def _run_verify_packs(args: argparse.Namespace) -> None:
                     print(f"    {err}")
                 all_ok = False
 
+    if not verified:
+        # Every platform skipped is no check at all: a mistyped or purged
+        # output directory read as a passed integrity check.
+        print(f"ERROR: no pack to verify in {args.output_dir}")
+        all_ok = False
     if not all_ok:
         sys.exit(1)
 

tests/test_audit_regressions.py

@@ -5019,6 +5019,18 @@ class ANamedPackThatIsAbsentFails(unittest.TestCase):
         self.assertIn("retroarch: FAIL (no pack in", result.stdout)
         self.assertIn("generate_pack.py --platform retroarch", result.stdout)
 
+    def test_all_with_no_pack_is_a_failure(self):
+        """--all on a mistyped or purged directory skipped every platform
+        and exited 0, a passed integrity check that checked nothing."""
+        with tempfile.TemporaryDirectory(dir=TMP_ROOT) as directory:
+            result = subprocess.run(
+                [sys.executable, "scripts/generate_pack.py", "--all",
+                 "--verify-packs", "--output-dir", directory],
+                cwd=ROOT, capture_output=True, text=True, timeout=600,
+            )
+        self.assertEqual(result.returncode, 1)
+        self.assertIn("no pack to verify", result.stdout)
+
 
 
 class AnAliasNamesItsProfile(unittest.TestCase):