Update

flutter/lib/src/integrations/native_app_start_integration.dart

@@ -114,9 +114,10 @@ class NativeAppStartIntegration extends Integration<SentryFlutterOptions> {
         // is not created therefore we need to create a transaction ourselves.
         // We detect this by checking if the currentRouteName is null.
         // This is a workaround since there is no api that tells us if
-        // the navigator observer exists or not.
+        // the navigator observer exists or not. The currentRouteName is always
+        // set during a didPush triggered by the navigator observer.
         if (SentryNavigatorObserver.currentRouteName == null) {
-          const screenName = 'root /';
+          const screenName = SentryNavigatorObserver.rootScreenName;
           // ignore: invalid_use_of_internal_member
           final transaction = hub.startTransaction(screenName, SentrySpanOperations.uiLoad,
               startTimestamp: appStartInfo.start);

flutter/lib/src/navigation/sentry_navigator_observer.dart

@@ -224,7 +224,7 @@ class SentryNavigatorObserver extends RouteObserver<PageRoute<dynamic>> {
     }
 
     if (name == '/') {
-      name = 'root /';
+      name = rootScreenName;
     }
     final transactionContext = SentryTransactionContext(
       name,
@@ -366,6 +366,10 @@ class SentryNavigatorObserver extends RouteObserver<PageRoute<dynamic>> {
     _completedDisplayTracking = Completer();
     _timeToDisplayTracker?.clear();
   }
+
+  /// The name of the rootScreen
+  @internal
+  static const String rootScreenName = 'root /';
 }
 
 /// This class makes it easier to record breadcrumbs for events of Flutters