fix: refuse a target --verify-packs cannot honour

An unknown target, or one the platform does not publish, was dropped and
the full pack verified under it with rc 0 (finding 34).

tests/test_target_verify.py

@@ -4,7 +4,8 @@
 under the target's name (Recalbox, Lakka, BizHawk, MiSTer, ROCKNIX). The
 conformance check read the same target without the --all tolerance, raised
 FileNotFoundError on the first of those packs and stopped the run in a
-traceback after every pack had been written.
+traceback after every pack had been written. Such a platform is now left
+out of a targeted --all run, and the check refuses it as the build does.
 """
 
 from __future__ import annotations
@@ -31,7 +32,10 @@ class CheckReadsTheTargetLikeTheBuild(unittest.TestCase):
                 contextlib.redirect_stdout(io.StringIO()):
             with self.assertRaises(ValueError):
                 build_target_cores_cache(["recalbox"], "x86_64", platforms, is_all=True)
-            self.assertIsNone(_target_cores_for("recalbox", "x86_64", platforms))
+        # The build never packs such a platform under the target, so the
+        # check refuses it too instead of reading the full pack.
+        with self.assertRaises(FileNotFoundError):
+            _target_cores_for("recalbox", "x86_64", platforms)
 
     def test_a_platform_with_a_target_file_is_narrowed(self):
         cores = _target_cores_for("retroarch", "switch", str(REPO_ROOT / "platforms"))

tests/test_verify_pack_choice.py

@@ -116,6 +116,24 @@ class VerifyPackChoice(unittest.TestCase):
             dict(zip((name for _p, name in checked), self.variants)), names
         )
 
+    def test_a_target_the_platform_lacks_is_refused(self):
+        """`--platform bizhawk --target rpi4typo --verify-packs` verified the
+        full pack and said `all OK`, where the build refused the target."""
+        import contextlib
+        import io
+
+        bizhawk = self.gp._platform_pack_stem(["bizhawk"], "bizhawk", "platforms")
+        self._touch(f"{bizhawk}_BIOS_Pack.zip")
+        self._touch(f"{self.stem}_BIOS_Pack.zip")
+        for platform, target in (("bizhawk", "rpi4typo"), ("retroarch", "swich")):
+            with self.subTest(platform=platform), \
+                    contextlib.redirect_stdout(io.StringIO()), \
+                    contextlib.redirect_stderr(io.StringIO()), \
+                    self.assertRaises(SystemExit) as ctx:
+                self._run(self._args(platform=platform, target=target))
+            self.assertEqual(ctx.exception.code, 1)
+            self.assertEqual(self.variants, [])
+
     def test_the_run_ends_on_a_summary(self):
         """A failing pack was named only above its own error lines, and the
         log ended on the last platform's OK line."""