std::process::exit to kill all threads

core/src/cluster_info.rs

@@ -2917,7 +2917,9 @@ impl ClusterInfo {
                                     self.id()
                                 );
                                 exit.store(true, Ordering::Relaxed);
-                                return;
+                                // TODO: Pass through ValidatorExit here so
+                                // that this will exit cleanly.
+                                std::process::exit(1);
                             }
                             _ => error!("gossip run_listen failed: {}", err),
                         }