Symbolize Android stacktrace (Flutter + Codemagic)

Turn an obfuscated Google Play Console crash/ANR stacktrace into a symbolized one (file + line for every native and Flutter frame), so you can reason about the bug.

When to use this

All three must hold — if any is false, this skill is the wrong tool:

1. The app is a Flutter app targeting Android.
2. The trace was exported from the Google Play Console (Crash dashboard or ANR dashboard) — typically a .txt/.log with pc 0x… frames, optionally a # Application: / # Version: header.
3. The release build was produced by Codemagic CI/CD, with the workflow uploading both android_native_debug_symbols.zip and <AppName>_<N>_artifacts.zip (Flutter's split-debug-info .symbols files) as build artefacts. Without those, there is nothing to match the obfuscated PCs against. mapping.txt (R8/ProGuard) is also pulled when present — it lets the symbolizer turn Ka.n.l+8 style Java frames back into io.flutter.embedding.engine.FlutterJNI.onSurfaceDestroyed, which is the difference between a readable Java side and a wall of obfuscated names.

If you're unsure whether the build was from Codemagic, check codemagic.yaml at the repo root or ask the user.

Setup (caller's machine)