fix: match profile_sync --system as verify does

--system compared the raw id, so the normalized spelling printed by verify.py --list-systems selected 1 Saturn profile of 11. The hint now counts the spellings that listing prints.

scripts/profile_sync.py

@@ -30,7 +30,13 @@ import yaml
 sys.path.insert(0, os.path.dirname(__file__))
 
 import upstream
-from common import github_token, load_emulator_profiles, suggest_names
+from common import (
+    _norm_system_id,
+    github_token,
+    load_emulator_profiles,
+    suggest_names,
+    system_index,
+)
 from hashing import parse_hash_list
 from sourceref import (  # noqa: F401  (re-exported for callers and tests)  # noqa: F401  (the prose grammar, re-exported)
     _ANNOTATION_RE,
@@ -3589,11 +3595,16 @@ def select_profiles(profiles: dict, args: argparse.Namespace) -> dict:
             )
         return {args.emulator: profiles[args.emulator]}
 
+    # --system matches as verify.py --list-systems lists and --system selects:
+    # by normalized id, so `saturn` reaches the profiles declaring sega-saturn.
+    wanted_system = _norm_system_id(args.system) if args.system else None
     selected = {}
     for name, profile in sorted(profiles.items()):
         if profile.get("type") in ("alias", "test"):
             continue
-        if args.system and args.system not in (profile.get("systems") or []):
+        if wanted_system and wanted_system not in {
+            _norm_system_id(str(s)) for s in profile.get("systems") or []
+        }:
             continue
         if args.type_ and profile.get("type") != args.type_:
             continue
@@ -3615,7 +3626,8 @@ def select_profiles(profiles: dict, args: argparse.Namespace) -> dict:
         )
         hint = ""
         if args.system:
-            systems = sorted({s for p in profiles.values() for s in p.get("systems") or []})
+            # Suggested from the spellings the named listing prints.
+            systems = sorted(spelling for spelling, _ in system_index(profiles).values())
             hint = " " + suggest_names([args.system], systems, "verify.py --list-systems")
         elif args.type_:
             kinds = sorted({str(p.get("type")) for p in profiles.values() if p.get("type")})

tests/test_profile_sync.py

@@ -4399,6 +4399,27 @@ class TestSelectionNamesWhatMatchedNothing(unittest.TestCase):
         selected = profile_sync.select_profiles(self.PROFILES, self._args(system="atari-lynx"))
         self.assertEqual(sorted(selected), ["handy", "mednafen_lynx"])
 
+    def test_system_matches_as_the_listing_does(self):
+        """verify.py --list-systems printed `saturn`, which selected 1 profile
+        of 11 because 10 declare sega-saturn."""
+        profiles = {
+            "a": {"type": "libretro", "systems": ["sega-saturn"]},
+            "b": {"type": "libretro", "systems": ["saturn"]},
+        }
+        for spelling in ("saturn", "sega-saturn"):
+            selected = profile_sync.select_profiles(profiles, self._args(system=spelling))
+            self.assertEqual(sorted(selected), ["a", "b"])
+
+    def test_the_hint_counts_what_the_listing_prints(self):
+        profiles = {
+            "a": {"type": "libretro", "systems": ["sega-saturn"]},
+            "b": {"type": "libretro", "systems": ["saturn"]},
+            "c": {"type": "libretro", "systems": ["atari-lynx"]},
+        }
+        with self.assertRaises(SystemExit) as caught:
+            profile_sync.select_profiles(profiles, self._args(system="nothing"))
+        self.assertIn("Known: atari-lynx, sega-saturn.", str(caught.exception.code))
+
 
 
 class TestTreeUrlIntoADirectory(unittest.TestCase):