Update README.md (#6)

README.md

@@ -12,8 +12,6 @@ Run `glance` in release or profile build, as detecting UI jank in debug mode is
 
 ### Start UI Jank Detection
 
-> `glance` works only when you build your application with the `--split-debug-info` option, see https://docs.flutter.dev/deployment/obfuscate#obfuscate-your-app for more detail. 
-
 To receive UI jank information, implement your own reporter (`JankDetectedReporter`). Once you have the jank information, you can save the stack traces to a file, or upload them to your server, and symbolize them using the `flutter symbolize` command.
 
 ```dart
@@ -37,16 +35,79 @@ void main() {
 }
 ```
 
+`glance` works only when you build your application with the `--split-debug-info` option (see [Flutter documentation](https://docs.flutter.dev/deployment/obfuscate#obfuscate-your-app)). For example, to build an Android APK:
+
+```
+flutter build apk --release --split-debug-info=debug-info
+```
+
 ### Symbolize the jank stack traces
 
-After obtaining the glance stack traces, you can use the `flutter symbolize` command to symbolize them. For more details, see [Flutter documentation](https://docs.flutter.dev/deployment/obfuscate#read-an-obfuscated-stack-trace)
+After obtaining the glance stack traces, you can use the `flutter symbolize` command (see [Flutter documentation](https://docs.flutter.dev/deployment/obfuscate#read-an-obfuscated-stack-trace)) to symbolize them. 
+
+For example, assume you get the stack traces from `info.stackTrace.toString()` in the above code on Android and save them to `my_stacktraces.txt` file:
+
+```
+// my_stacktraces.txt
+
+*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
+pid: 32542, tid: 32575, name 1.ui
+os: android arch: arm64 comp: yes sim: no
+build_id: '4dbecf547733e72ae1688d73ebb5f062'
+isolate_dso_base: 7de0e44000, vm_dso_base: 7de0e44000
+isolate_instructions: 7de0efa840, vm_instructions: 7de0ee4000
+    #00 abs 0000007de0f63ae8 _kDartIsolateSnapshotInstructions+0x692a8
+    #01 abs 0000007de0f63a04 _kDartIsolateSnapshotInstructions+0x691c4
+    #02 abs 0000007de0fed7a8 _kDartIsolateSnapshotInstructions+0xf2f68
+    #03 abs 0000007de10611b0 _kDartIsolateSnapshotInstructions+0x166970
+    #04 abs 0000007de0facecc _kDartIsolateSnapshotInstructions+0xb268c
+    #05 abs 0000007de106b3a0 _kDartIsolateSnapshotInstructions+0x170b60
+    #06 abs 0000007de1023900 _kDartIsolateSnapshotInstructions+0x1290c0
+    #07 abs 0000007de102320c _kDartIsolateSnapshotInstructions+0x1289cc
+    #08 abs 0000007de10231d0 _kDartIsolateSnapshotInstructions+0x128990
+    #09 abs 0000007de106c248 _kDartIsolateSnapshotInstructions+0x171a08
+    #10 abs 0000007de106bfd4 _kDartIsolateSnapshotInstructions+0x171794
+
+```
+
+After running the `flutter symbolize` command:
+
+```
+flutter symbolize -i my_stacktraces.txt -d debug-info/app.android-arm64.symbols
+```
+
+You can get the symbolized stack traces like this:
+
+```
+*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
+pid: 32542, tid: 32575, name 1.ui
+os: android arch: arm64 comp: yes sim: no
+build_id: '4dbecf547733e72ae1688d73ebb5f062'
+isolate_dso_base: 7de0e44000, vm_dso_base: 7de0e44000
+isolate_instructions: 7de0efa840, vm_instructions: 7de0ee4000
+#0      jsonEncode (third_party/dart/sdk/lib/convert/json.dart:114:10)
+#1      expensiveFunction (/my/project/jank_app.dart:22:5)
+#2      _BuildPhaseJankWidgetState.build (/my/project/build_phase_jank_test.dart:26:3)
+#3      StatefulElement.build (/my/path/flutter/packages/flutter/lib/src/widgets/framework.dart:5592:3)
+#4      Element.widget (/my/path/flutter/packages/flutter/lib/src/widgets/framework.dart)
+#5      ComponentElement.performRebuild (/my/path/flutter/packages/flutter/lib/src/widgets/framework.dart:5486:31)
+#6      StatefulElement.performRebuild (/my/path/flutter/packages/flutter/lib/src/widgets/framework.dart:5638:3)
+#7      List.iterator (third_party/dart/sdk/lib/_internal/vm/lib/growable_array.dart:507:16)
+#8      BuildOwner.buildScope (/my/path/flutter/packages/flutter/lib/src/widgets/framework.dart:2952:37)
+#9      WidgetsBinding.drawFrame (/my/path/flutter/packages/flutter/lib/src/widgets/binding.dart:1230:13)
+#10     RendererBinding._handlePersistentFrameCallback (/my/path/flutter/packages/flutter/lib/src/rendering/binding.dart:469:5)
+```
 
 ### Symbolize Automatically
 Some tools, like Firebase and Sentry, can automatically symbolize the stack traces if you upload the symbols. This is helpful if you do not have a self-hosted server.
 See more detail:
 - Firebase: https://firebase.google.com/docs/crashlytics/get-deobfuscated-reports?platform=flutter
 - Sentry: https://docs.sentry.io/platforms/flutter/upload-debug/
 
+## Known issues
+
+In some cases, the stack traces may not accurately reflect the exact invocation order of the Dart code. This issue requires further improvement.
+
 ## Acknowledgements
 
 Thanks to [thread_collect_stack_example](https://github.com/mraleph/thread_collect_stack_example) for the inspiration, which made this project possible.