test(#829): regress prefixed runtime variable launches

packages/mosaic/src/mutator-gate/runtime_launch_guard_unittest.py

@@ -76,6 +76,22 @@ class RuntimeLaunchGuardTest(unittest.TestCase):
             with self.subTest(filename=filename):
                 self.assertEqual(GUARD.scan_text(Path(filename), source), [])
 
+    def test_detects_prefixed_tracked_runtime_variable_execution(self) -> None:
+        multiline = {
+            "exec-quoted": 'exec "$v" -p x',
+            "exec-unquoted": "exec $v -p x",
+            "command": 'command "$v" -p x',
+            "nohup": 'nohup "$v" -p x',
+            "env": 'env A=1 "$v" -p x',
+        }
+        cases = {
+            **{f"multiline-{name}.sh": f"v=claude\n{command}\n" for name, command in multiline.items()},
+            **{f"same-line-{name}.sh": f"v=claude; {command}\n" for name, command in multiline.items()},
+        }
+        for filename, source in cases.items():
+            with self.subTest(filename=filename):
+                self.assertNotEqual(GUARD.scan_text(Path(filename), source), [], source)
+
     def test_accepts_only_validated_multiline_typescript_wrapper_invocation(self) -> None:
         source = """execRuntime(
   'python3',