fix: index regions over the platform's own cores

scripts/generate_pack.py

@@ -474,7 +474,9 @@ def _select_variants(
             required_only=required_only,
         )
     if regions:
-        region_index = region_mod.build_region_index(emu_profiles or {})
+        region_index = region_mod.platform_region_index(
+            config, emu_profiles or {}, target_cores
+        )
         region_drops = region_mod.resolve_region_drops(
             region_groups, region_index, regions
         )
@@ -3366,7 +3368,9 @@ def _manifest_selection(
         required_only=required_only,
         extras_out=extras,
     )
-    region_index = region_mod.build_region_index(emu_profiles)
+    region_index = region_mod.platform_region_index(
+        config, emu_profiles, target_cores
+    )
     drops = (
         region_mod.resolve_region_drops(region_groups, region_index, regions)
         if regions

scripts/packverify.py

@@ -572,7 +572,9 @@ def verify_pack_against_platform(
 
     region_drops: set[str] = set()
     if regions:
-        region_index = region_mod.build_region_index(emu_profiles)
+        region_index = region_mod.platform_region_index(
+            config, emu_profiles, target_cores
+        )
         region_groups, _extra_dests = platform_region_groups(
             config,
             expected_systems,

scripts/region.py

@@ -125,6 +125,22 @@ def region_tag(requested: list[str]) -> str:
     )
 
 
+def platform_region_index(
+    config: dict, profiles: dict, target_cores: set[str] | None = None
+) -> dict[str, dict]:
+    """The region index of the emulators a platform runs, nothing else.
+
+    Built over every profile, an emulator foreign to the platform voided the
+    filter: Pizza Boy SC, an Android app, declares bios_CD_E.bin without a
+    region, so the Genesis Plus GX and PicoDrive tags never counted and
+    `--region us` kept both CD BIOSes in the RetroArch pack.
+    """
+    from common import resolve_platform_cores
+
+    cores = resolve_platform_cores(config, profiles, target_cores=target_cores)
+    return build_region_index({n: profiles[n] for n in cores if n in profiles})
+
+
 def build_region_index(profiles: dict) -> dict[str, dict]:
     """Build a region lookup from emulator profiles.
 

scripts/verify.py

@@ -973,7 +973,9 @@ def verify_platform(
             target_cores=target_cores,
         )
         region_drops = region_mod.resolve_region_drops(
-            region_groups, region_mod.build_region_index(profiles), regions
+            region_groups,
+            region_mod.platform_region_index(config, profiles, target_cores),
+            regions,
         )
 
     # A destination two systems declare with two hashes ships one file, the