add list of components that failed to shut down in time to panic msg

src/topology/running.rs

@@ -152,7 +152,7 @@ impl RunningTopology {
                     components = ?remaining_components,
                     "Failed to gracefully shut down in time. Killing components."
                 );
-                Result::Err(())
+                Result::Err(remaining_components)
             }) as future::BoxFuture<'static, Result<(), ()>>
         } else {
             Box::pin(future::pending()) as future::BoxFuture<'static, Result<(), ()>>
@@ -195,18 +195,18 @@ impl RunningTopology {
 
         // Aggregate future that ends once anything detects that all tasks have shutdown.
         let shutdown_complete_future = future::select_all(vec![
-            Box::pin(timeout) as future::BoxFuture<'static, Result<(), ()>>,
-            Box::pin(reporter.map(|()| Result::<(), ()>::Ok(()))) as future::BoxFuture<'static, Result<(), ()>>,
-            Box::pin(success) as future::BoxFuture<'static, Result<(), ()>>,
+            Box::pin(timeout) as future::BoxFuture<'static, Result<(), String>>,
+            Box::pin(reporter.map(|()| Result::<(), String>::Ok(()))) as future::BoxFuture<'static, Result<(), String>>,
+            Box::pin(success) as future::BoxFuture<'static, Result<(), String>>,
         ]);
 
         // Now kick off the shutdown process by shutting down the sources.
-        let source_shutdown_complete = self.shutdown_coordinator.shutdown_all(deadline).map(|_| Result::<(), ()>::Ok(()));
+        let source_shutdown_complete = self.shutdown_coordinator.shutdown_all(deadline).map(|_| Result::<(), String>::Ok(()));
 
         // Panic to ensure that Vector returns a non-zero exit code when it's unable to gracefully shutdown
         futures::future::join(source_shutdown_complete, shutdown_complete_future)
             .map(|futures| match futures.1.0 {
-                Result::Err(_) => panic!("failed to gracefully shutdown in time, panic to force non-zero exit code"),
+                Result::Err(s) => panic!(format!("failed to gracefully shutdown in time, panic to force non-zero exit code: {s}")),
                 Result::Ok(_) => (),
             })
     }