Mobile Debug
One debugging process for every mobile stack. This file holds how to find a cause; each platform's error signatures and fixes live in its reference.
1. Pick the reference
Choose by the stack and by the layer the error comes from — a Flutter or React Native build often fails inside Gradle or Xcode:
| The failure is in |
Read |
| A Flutter app: pub, Dart compilation, generated code, widgets, runtime exceptions |
references/flutter.md |
Gradle, the Android build, logcat crashes or ANRs (native Android, or the android/ folder of any app) |
references/android.md |
Xcode, signing, CocoaPods, Swift packages or iOS crash logs (native iOS, or the ios/ folder of any app) |
references/ios.md |
| A React Native or Expo app: Metro, native modules, JavaScript errors |
references/react-native.md |
| Kotlin Multiplatform compilation, source-set or framework integration |
references/kotlin-multiplatform.md |
| A deep link, App Link or Universal Link that opens the browser, the wrong screen or crashes (any stack) |
references/deep-links.md |
When reis-mobile debug (or /reis-mobile:debug) ran, its area line points at the layer: gradle, manifest, proguard → Android; xcode, signing, cocoapods, spm → iOS; pub → Flutter; metro → React Native.
2. Find the first real error
Build and crash logs bury the cause under cascading failures. Quote the line that starts the failure — the first error:, the What went wrong block, the top of the exception with its Caused by — not the final BUILD FAILED or the last frame. Ask for the full output when the user pasted only the end.
3. Collect versions before theorizing
Most build failures after an upgrade are toolchain mismatches. Read the versions that decide the behavior — the SDK and toolchain versions (the doctor report shows them), wrapper and lock files, build scripts, deployment targets — and quote them in the diagnosis. Check compatibility against the official tables named in the reference; do not state compatibility ranges from memory.
4. Reproduce safely
Read-only commands can run: version checks, dependency trees, flutter doctor -v, ./gradlew --version, pod --version, xcodebuild -version. A build that only compiles can run when the user already ran it or agrees, since it takes time and writes build outputs.
5. Confirm the cause
Tie the cause to evidence: file:line, a version, a build setting or a log line. If two causes are plausible, say what evidence would separate them instead of picking one.
6. Propose, then wait
Answer with:
- Cause — one or two sentences, with the evidence.
- Fix — the minimal change, as a diff or exact commands, in order.
- Side effects — what else the fix changes: a higher minimum Android or iOS version, a Gradle or Kotlin upgrade that CI needs too, pods changing version.
- Verify — the command that failed, run again.
Do not edit files, upgrade dependencies or run commands that change the project, the caches or the machine — flutter clean, pod install, pod repo update, npx expo prebuild --clean, deleting DerivedData, ~/.gradle caches or node_modules — until the user asks you to apply the fix. Then apply it, run the verification and report the result.
1---2name: mobile-debug3description: Diagnoses build and runtime failures across Flutter, native Android, native iOS, React Native and Kotlin Multiplatform. Covers pub/Dart, Gradle/AGP, Xcode/CocoaPods, Metro, KMP source sets and iOS frameworks, crashes and deep links. Use for failing builds, app launches, stack traces or /reis-mobile:debug.4---56# Mobile Debug78One debugging process for every mobile stack. This file holds how to find a cause; each platform's error signatures and fixes live in its reference.910## 1. Pick the reference1112Choose by the stack **and** by the layer the error comes from — a Flutter or React Native build often fails inside Gradle or Xcode:1314| The failure is in | Read |15|---|---|16| A Flutter app: pub, Dart compilation, generated code, widgets, runtime exceptions | [references/flutter.md](references/flutter.md) |17| Gradle, the Android build, logcat crashes or ANRs (native Android, or the `android/` folder of any app) | [references/android.md](references/android.md) |18| Xcode, signing, CocoaPods, Swift packages or iOS crash logs (native iOS, or the `ios/` folder of any app) | [references/ios.md](references/ios.md) |19| A React Native or Expo app: Metro, native modules, JavaScript errors | [references/react-native.md](references/react-native.md) |20| Kotlin Multiplatform compilation, source-set or framework integration | [references/kotlin-multiplatform.md](references/kotlin-multiplatform.md) |21| A deep link, App Link or Universal Link that opens the browser, the wrong screen or crashes (any stack) | [references/deep-links.md](references/deep-links.md) |2223When `reis-mobile debug` (or `/reis-mobile:debug`) ran, its `area` line points at the layer: `gradle`, `manifest`, `proguard` → Android; `xcode`, `signing`, `cocoapods`, `spm` → iOS; `pub` → Flutter; `metro` → React Native.2425## 2. Find the first real error2627Build and crash logs bury the cause under cascading failures. Quote the line that starts the failure — the first `error:`, the `What went wrong` block, the top of the exception with its `Caused by` — not the final `BUILD FAILED` or the last frame. Ask for the full output when the user pasted only the end.2829## 3. Collect versions before theorizing3031Most build failures after an upgrade are toolchain mismatches. Read the versions that decide the behavior — the SDK and toolchain versions (the doctor report shows them), wrapper and lock files, build scripts, deployment targets — and quote them in the diagnosis. Check compatibility against the official tables named in the reference; do not state compatibility ranges from memory.3233## 4. Reproduce safely3435Read-only commands can run: version checks, dependency trees, `flutter doctor -v`, `./gradlew --version`, `pod --version`, `xcodebuild -version`. A build that only compiles can run when the user already ran it or agrees, since it takes time and writes build outputs.3637## 5. Confirm the cause3839Tie the cause to evidence: `file:line`, a version, a build setting or a log line. If two causes are plausible, say what evidence would separate them instead of picking one.4041## 6. Propose, then wait4243Answer with:4445- **Cause** — one or two sentences, with the evidence.46- **Fix** — the minimal change, as a diff or exact commands, in order.47- **Side effects** — what else the fix changes: a higher minimum Android or iOS version, a Gradle or Kotlin upgrade that CI needs too, pods changing version.48- **Verify** — the command that failed, run again.4950Do not edit files, upgrade dependencies or run commands that change the project, the caches or the machine — `flutter clean`, `pod install`, `pod repo update`, `npx expo prebuild --clean`, deleting `DerivedData`, `~/.gradle` caches or `node_modules` — until the user asks you to apply the fix. Then apply it, run the verification and report the result.
wrsilva