fix shutdown

spot/spot_manager.py

@@ -353,11 +353,14 @@ class SpotManager(object):
         # SEND SHUTDOWN TO EACH INSTANCE
         Log.warning("Shutdown {{instances}} to save money!", instances=remove_list.id)
         for g, removals in jx.groupby(remove_list, size=20):
-            for t in [
-                Thread.run("teardown " + i.id, self.instance_manager.teardown, i, please_stop=False)
+            for i, t in [
+                (i, Thread.run("teardown " + i.id, self.instance_manager.teardown, i, please_stop=False))
                 for i in removals
             ]:
-                t.join()
+                try:
+                    t.join()
+                except Exception:
+                    Log.note("Problem with shutdown of {{id}}", id=i.id)
 
         remove_spot_requests.extend(remove_list.spot_instance_request_id)