flutter: Add stack_trace

See: https://pub.dev/packages/stack_trace

src/ui/flutter/lib/main.dart

@@ -16,6 +16,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+import 'dart:async';
 import 'dart:io';
 
 import 'package:catcher/catcher.dart';
@@ -24,6 +25,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:sanmill/generated/l10n.dart';
+import 'package:stack_trace/stack_trace.dart';
 
 import 'services/audios.dart';
 import 'services/player.dart';
@@ -103,7 +105,9 @@ class _SanmillAppState extends State<SanmillApp> {
   @override
   void initState() {
     super.initState();
-    Player.loadProfile();
+    Chain.capture(() {
+      Player.loadProfile();
+    });
   }
 
   @override

src/ui/flutter/pubspec.yaml

@@ -20,6 +20,7 @@ dependencies:
   intl: ^0.16.1
   flutter_socket_io: ^0.6.0
   catcher: ^0.4.1
+  stack_trace: ^1.9.6
 
 dev_dependencies:
   flutter_test: