Crash Reporting and Symbolicated Stack Traces

When you ship a Flutter app in release mode, the Dart compiler produces optimized AOT machine code and strips human-readable symbols. A crash that happens in production no longer reports UserRepository.fetchProfile — it reports a hex offset like #00 abs 0000007f9c2a1b40.

• Debug builds keep symbols, so traces are readable locally.
• Release builds obfuscate and strip, so the on-device trace is just addresses.
• To turn those addresses back into method names you need symbolication (native iOS/Android symbols) and deobfuscation (Dart symbol mapping).

This lesson wires up Crashlytics and Sentry so every production crash arrives fully symbolicated and actionable.

Flutter obfuscation is opt-in. You enable it at build time and Flutter writes a Dart symbol map per target architecture into a directory you choose.

• --obfuscate renames Dart identifiers to short tokens.
• --split-debug-info writes the mapping files (e.g. app.android-arm64.symbols) so you can reverse the obfuscation later.

You must archive these symbol files per release. Without the exact file that matches the shipped binary, the trace can never be deobfuscated.