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)