more graceful handling of intentional node crashing

nucypher/blockchain/eth/actors.py

@@ -577,8 +577,8 @@ class Operator(BaseActor):
             self.check_ferveo_public_key_match()
         except FerveoKeyMismatch:
             # crash this node
-            self.stop()
-            exit()
+            self.stop(halt_reactor=True)
+            return
 
         if self.checksum_address not in participants:
             message = (

nucypher/characters/lawful.py

@@ -994,7 +994,11 @@ class Ursula(Teacher, Character, Operator):
             if self._prometheus_metrics_tracker:
                 self._prometheus_metrics_tracker.stop()
         if halt_reactor:
-            reactor.stop()
+            self.halt_reactor()
+
+    @staticmethod
+    def halt_reactor() -> None:
+        reactor.stop()
 
     def _finalize(self):
         """

tests/fixtures.py

@@ -836,3 +836,8 @@ def mock_async_hooks(mocker):
     )
 
     return hooks
+
+
+@pytest.fixture(scope="session", autouse=True)
+def mock_halt_reactor(session_mocker):
+    session_mocker.patch.object(Ursula, "halt_reactor")