wait for interface to close

pkg/task/runner.go

@@ -110,6 +110,9 @@ func (r *TaskRunner) Run(ctx context.Context, t Tasker, i Interface, iType Inter
 		close(stopChan)
 		close(quitChan)
 		collector.setCompleted(true)
+		if err := <-interfaceErr; err != nil {
+			return fmt.Errorf("task interface failed during shutdown: %w", err)
+		}
 
 	case err := <-interfaceErr:
 		close(stopChan)