fix: refuse a --bios-dir that does not exist

scripts/auto_fetch.py

@@ -29,6 +29,7 @@ from pathlib import Path
 
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
 from common import (
+    require_directory,
     list_registered_platforms,
     load_database,
     load_platform_config,
@@ -429,6 +430,7 @@ def main() -> None:
         "--create-issues", action="store_true", help="Output GitHub Issue bodies"
     )
     args = parser.parse_args()
+    require_directory(args.bios_dir)
 
     if not os.path.exists(args.db):
         print(f"Error: {args.db} not found. Run generate_db.py first.", file=sys.stderr)

scripts/common.py

@@ -31,6 +31,17 @@ except ImportError:
 
 
 
+def require_directory(path: str, flag: str = "--bios-dir") -> None:
+    """Stop on a folder that does not exist.
+
+    identity --strict, dedup, auto_fetch, romset_recipes and generate_pack
+    read a mistyped --bios-dir as an empty collection and passed: 0
+    conflicts, 0 duplicates, a pack of nothing.
+    """
+    if not os.path.isdir(path):
+        raise SystemExit(f"ERROR: {flag} {path} is not a directory")
+
+
 class DatabaseUnreadable(FileNotFoundError):
     """The database a command was pointed at does not exist or is not JSON."""
 

scripts/dedup.py

@@ -28,7 +28,7 @@ from collections import defaultdict
 from pathlib import Path
 
 sys.path.insert(0, os.path.dirname(__file__))
-from common import compute_hashes, write_text_atomic
+from common import compute_hashes, require_directory, write_text_atomic
 
 DEFAULT_BIOS_DIR = "bios"
 
@@ -319,6 +319,7 @@ def main() -> None:
     )
     parser.add_argument("--bios-dir", default=DEFAULT_BIOS_DIR)
     args = parser.parse_args()
+    require_directory(args.bios_dir)
 
     print(f"Scanning {args.bios_dir}/ for duplicates...")
     if args.dry_run:

scripts/generate_pack.py

@@ -33,6 +33,7 @@ from pathlib import Path
 sys.path.insert(0, os.path.dirname(__file__))
 from common import resolve_platform_cores as _platform_cores
 from common import (
+    require_directory,
     target_listing_line,
     suggest_names,
     require_platform,
@@ -2977,6 +2978,7 @@ def _main(held: contextlib.ExitStack) -> None:
     packresolve.set_offline(bool(args.offline))
     if args.platform:
         require_platform(args.platform, args.platforms_dir)
+    require_directory(args.bios_dir)
 
     _refuse_unapplied_flags(args, parser)
     # Quick-exit modes: --verify-packs alone = verify existing packs only

scripts/identity.py

@@ -151,6 +151,9 @@ def main() -> int:
         "--strict", action="store_true", help="exit non-zero when any is found"
     )
     args = parser.parse_args()
+    from common import require_directory  # noqa: PLC0415
+
+    require_directory(args.bios_dir)
 
     duplicates = scan(args.bios_dir)
     if args.json:

scripts/romset_recipes.py

@@ -35,6 +35,7 @@ from pathlib import Path
 sys.path.insert(0, str(Path(__file__).resolve().parent))
 
 from common import (
+    require_directory,
     load_database,
     load_emulator_profiles,
     load_platform_config,
@@ -471,6 +472,7 @@ def main() -> int:
         help="recipe snapshot file, or a directory of them",
     )
     args = parser.parse_args()
+    require_directory(args.bios_dir)
     _resolve_modes(args)
 
     db = load_database(args.db)

tests/test_system_selection.py

@@ -208,6 +208,41 @@ class AMissingDatabaseIsNamed(unittest.TestCase):
                 self.assertIn("nosuch.json", proc.stderr)
 
 
+class AMissingBiosDirIsRefused(unittest.TestCase):
+    """identity --strict passed on a mistyped --bios-dir with "0 contents",
+    dedup saved 0 MB, and generate_pack wrote a pack of nothing: a folder
+    that does not exist read as an empty collection."""
+
+    EXTRA = {
+        "auto_fetch.py": ["--platform", "batocera", "--dry-run"],
+        "generate_pack.py": ["--platform", "batocera", "--offline", "--output-dir", "{out}"],
+        "dedup.py": ["--dry-run"],
+        "identity.py": ["--strict"],
+    }
+
+    def test_every_script_taking_a_bios_dir_refuses_a_missing_one(self):
+        scratch = tempfile.TemporaryDirectory(dir=REPO_ROOT / "tmp")
+        self.addCleanup(scratch.cleanup)
+        out = str(Path(scratch.name) / "out")
+        taking = sorted(
+            path.name for path in (REPO_ROOT / "scripts").glob("*.py")
+            if re.search(r'add_argument\(\s*"--bios-dir"', path.read_text(encoding="utf-8"))
+            and path.name != "generate_db.py"
+        )
+        self.assertGreater(len(taking), 4)
+        for script in taking:
+            extra = [arg.format(out=out) for arg in self.EXTRA.get(script, [])]
+            with self.subTest(script=script):
+                proc = subprocess.run(
+                    [sys.executable, f"scripts/{script}", "--bios-dir", "nosuch", *extra],
+                    capture_output=True, text=True, cwd=str(REPO_ROOT), timeout=600,
+                    check=False,
+                )
+                self.assertNotEqual(proc.returncode, 0)
+                self.assertIn("--bios-dir nosuch is not a directory", proc.stderr)
+        self.assertFalse(Path(out).exists())
+
+
 class StrictVerifyFailsOnACriticalMiss(unittest.TestCase):
     """verify exited 0 with a required file missing on an md5 platform, so
     the pipeline printed "verify OK" over a pack the frontend rejects."""