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.

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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:

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