# Apple Crash Symbolication

Symbolicate .NET runtime frames in Apple platform .ips crash logs (iOS, tvOS, Mac...

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

## Description

Symbolicate .NET runtime frames in Apple platform .ips crash logs (iOS, tvOS, Mac Catalyst, macOS). Extracts UUIDs and addresses from the native backtrace, locates dSYM debug symbols, and runs atos to produce function names with source file and line numbers. Automatically downloads .dwarf symbols from the Microsoft symbol server using Mach-O UUIDs. USE FOR triaging a .NET MAUI or Mono app crash from an .ips file on any Apple platform, resolving native backtrace frames in libcoreclr or libmonosgen-2.0 to .NET runtime source code, retrieving .ips crash logs from a connected iOS device or iPhone, or investigating EXC_CRASH, EXC_BAD_ACCESS, SIGABRT, or SIGSEGV originating from the .NET runtime. DO NOT USE FOR pure Swift/Objective-C crashes with no .NET components, or Android tombstone files. INVOKES Symbolicate-Crash.ps1 script, atos, dwarfdump, idevicecrashreport.

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

# Apple Platform Crash Log .NET Symbolication

Resolves native backtrace frames from .NET MAUI and Mono app crashes on Apple platforms (iOS, tvOS, Mac Catalyst, macOS) to function names, source files, and line numbers using Mach-O UUIDs and dSYM debug symbol bundles.

**Inputs:** Crash log file (`.ips` JSON format, iOS 15+ / macOS 12+), `atos` (from Xcode), optionally a connected iOS device to pull crash logs from.

**Do not use when:** The crashing library is not a .NET component (e.g., pure Swift/UIKit), or the crash log is an Android tombstone.

---

## Workflow

### Step 1: Parse the .ips Crash Log

**Format check:** Before proceeding, verify the file is `.ips` JSON format. The first line must be valid JSON. If the file is plain text (e.g., Android tombstone with `#NN pc` frame lines, or legacy Apple `.crash` text format), **stop immediately**, this workflow does not apply. Report the format mismatch to the user and do not attempt any symbolication.

The `.ips` file is **two-part JSON**: line 1 is a metadata header; the remaining lines are a separate JSON crash body. Parse them separately:

```python
lines = open('crash.ips').readlines()
metadata = json.loads(lines[0])           # app_name, bundleID, os_version, slice_uuid
crash    = json.loads(''.join(lines[1:])) # Full crash report
```

Key fields in the crash body:
- `usedImages[N]` has `name`, `base` (load address), `uuid`, `arch` for each loaded binary
- `threads[N].frames[M]` has `imageOffset`, `imageIndex`; frame address = `usedImages[imageIndex].base + imageOffset`
- `exception.type`, `exception.signal` (e.g., `EXC_CRASH` / `SIGABRT`)
- `asi` (Application Specific Information) often contains the managed exception message
- `lastExceptionBacktrace` has frames from the exception that triggered the crash
- `faultingThread` is the index into the `threads` array

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