# Android Tombstone Symbolication

Symbolicate the .NET runtime frames in an Android tombstone file.

- Repository: https://github.com/dotnet/skills (5787 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add dotnet/skills --skill android-tombstone-symbolication -g -a claude-code -y`
Codex: `npx skills add dotnet/skills --skill android-tombstone-symbolication -g -a codex -y`
Cursor: `npx skills add dotnet/skills --skill android-tombstone-symbolication -g -a cursor -y`
Gemini CLI: `npx skills add dotnet/skills --skill android-tombstone-symbolication -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add dotnet/skills`

## Description

Symbolicate the .NET runtime frames in an Android tombstone file. Extracts BuildIds and PC offsets from the native backtrace, downloads debug symbols from the Microsoft symbol server, and runs llvm-symbolizer to produce function names with source file and line numbers. USE FOR triaging a .NET MAUI or Mono Android app crash from a tombstone, resolving native backtrace frames in libmonosgen-2.0.so or libcoreclr.so to .NET runtime source code, or investigating SIGABRT, SIGSEGV, or other native signals originating from the .NET runtime on Android. DO NOT USE FOR pure Java/Kotlin crashes, managed .NET exceptions that are already captured in logcat, or iOS crash logs. INVOKES Symbolicate-Tombstone.ps1 script, llvm-symbolizer, Microsoft symbol server.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Android Tombstone .NET Symbolication

Resolves native backtrace frames from .NET Android app crashes (MAUI, Xamarin, Mono) to function names, source files, and line numbers using ELF BuildIds and Microsoft's symbol server.

**Inputs:** Tombstone file or logcat crash output, `llvm-symbolizer` (from Android NDK or any LLVM 14+ toolchain), internet access for symbol downloads.

**Do not use when:** The crash is a managed .NET exception (visible in logcat with a managed stack trace), the crashing library is not a .NET component (e.g., `libart.so`), or the tombstone is from iOS.

---

## Workflow

### Step 1: Parse the Tombstone Backtrace

Each backtrace frame has this format:

```
#NN pc OFFSET  /path/to/library.so (optional_symbol+0xNN) (BuildId: HEXSTRING)
```

Extract: **frame number**, **PC offset** (hex, already library-relative), **library name**, and **BuildId** (32, 40 hex chars).

Symbolicate all threads by default (background threads like GC/finalizer often have useful .NET frames). The crashing thread's backtrace is listed first; additional threads appear after `--- --- ---` markers.

**Format notes:**
- The script auto-detects `#NN pc` frame lines with or without a `backtrace:` header, and strips logcat timestamp/tag prefixes automatically.
- Logcat-captured tombstones often omit BuildIds. Recover via `adb shell readelf -n`, CI build artifacts, or the .NET runtime NuGet package.
- GitHub issue pastes may mangle `#1 pc` into issue links, replace `org/repo#N pc` with `#N pc` before saving to a file.
- If the script fails to parse a format, fall back to manual extraction of `#NN pc OFFSET library.so (BuildId: HEX)` tuples.

### Step 2: Identify .NET Runtime Libraries

Filter frames to .NET runtime libraries:

The rest: https://github.com/dotnet/skills/blob/HEAD/plugins/dotnet-diag/skills/android-tombstone-symbolication/SKILL.md