Crash Instrumentation
Capture crashes with the context needed to debug them.
Core Principle
A crash report without context is useless. Every crash should include:
| Context |
Why |
Example |
screen |
Where it happened |
"CheckoutScreen" |
job_name |
What user was doing |
"checkout" |
job_step |
Where in the flow |
"payment" |
breadcrumbs |
What led here |
Last 20 user actions |
app_version |
Release correlation |
"1.2.3" |
user_segment |
Who's affected |
"premium", "trial" |
Breadcrumb Strategy
Breadcrumbs are the trail leading to a crash. Capture:
| Category |
What to Log |
Example |
navigation |
Screen transitions |
"HomeScreen → CartScreen" |
user |
Taps, inputs, gestures |
"Tapped checkout button" |
network |
API calls (not payloads) |
"POST /api/orders started" |
state |
Key state changes |
"Cart updated: 3 items" |
error |
Non-fatal errors |
"Retry #2 for payment" |
Limit: Keep last 20-50 breadcrumbs. More is noise.
Error Boundaries
Catch errors before they crash the app:
// iOS - capture context before crash
func captureError(_ error: Error, screen: String, job: String?) {
Observability.captureError(error, context: [
"screen": screen,
"job_name": job ?? "unknown",
"session_duration": sessionDuration(),
"memory_pressure": memoryPressure()
])
}
// Android - uncaught exception handler
Thread.setDefaultUncaughtExceptionHandler { thread, throwable ->
Observability.captureError(throwable, mapOf(
"thread" to thread.name,
"screen" to currentScreen,
"job_name" to currentJob
))
previousHandler?.uncaughtException(thread, throwable)
}
What NOT to Attach
| Don't |
Why |
| Full stack traces in breadcrumbs |
Redundant, SDK captures this |
| User input text |
PII risk |
| Full request/response bodies |
Size limits, PII |
| Entire app state |
Unbounded, noise |
Crash Types to Handle
| Platform |
Type |
Instrumentation |
| iOS |
EXC_BAD_ACCESS |
Breadcrumbs, memory context |
| iOS |
SIGKILL (watchdog) |
Background task tracking |
| Android |
ANR |
Main thread breadcrumbs |
| Android |
OutOfMemoryError |
Memory tracking |
| React Native |
JS exceptions |
Error boundaries |
Implementation
See references/crash-reporting.md for:
- Platform-specific crash capture setup
- Breadcrumb implementation patterns
- Vendor SDK configuration
See skills/symbolication-setup for readable stack traces.
