macOS Tcc Sigkill Missing Usage Description

What it does

When your agent uses it

• App crashes immediately when touching Photos
• Screen Recording
• Crash report shows Exception: EXCCRASH (SIGKILL) with Termination namespace: TCC
• Crash stack includes TCC.TCCCRASHINGDUETOPRIVACYVIOLATION

Example prompts

• “/macos-tcc-sigkill-missing-usage-description”

Requirements

• Python 3

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Read the crash report's termination details — it names the exact key.
2. 2Add the key to your app's Info.plist
3. 3If the app is sandboxed (com.apple.security.app-sandbox = true in release),
4. 4Rebuild. Info.plist changes do not hot-reload in Flutter — a full
5. 5Relaunch the app.

What it can do on your machine

Read from SKILL.md and the folder at commit 4c622be. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • flutter
  • python3

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • developer.apple.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

macOS Tcc Sigkill Missing Usage Description loads about 2.2k tokens when it runs. Until then it costs about 239 tokens; SKILL.md has 763 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~239

When it runs · the whole SKILL.md, loaded when a task matches

~2.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from divinevideo/divine-mobile at commit 4c622be, republished under its MPL-2.0 licence (© divinevideo). 763 words, ~2,244 tokens.

name

macos-tcc-sigkill-missing-usage-description

description

Fix macOS app hard crashes (EXC_CRASH / SIGKILL) caused by accessing TCC-protected APIs without the matching Info.plist usage description key. Use when: (1) App crashes immediately when touching Photos, Contacts, Calendar, Reminders, Location, Microphone, Camera, Screen Recording, etc., (2) Crash report shows `Exception: EXC_CRASH (SIGKILL)` with `Termination namespace: TCC`, (3) Crash stack includes `TCC.__TCC_CRASHING_DUE_TO_PRIVACY_VIOLATION__`, (4) Termination details contain "This app has crashed because it attempted to access privacy-sensitive data without a usage description", (5) Flutter macOS publish / gallery-save flow crashes on Gal.putVideo, PHPhotoLibrary, CNContactStore, etc. Critical distinction: macOS does NOT return a deny error — it SIGKILLs the process. This skill also covers the NSPhotoLibraryUsageDescription vs NSPhotoLibraryAddUsageDescription distinction that trips many apps.

author

Claude Code

version

1.0.0

date

2026-04-05

<!-- mobile/macos/Runner/Info.plist -->
<key>NSPhotoLibraryAddUsageDescription</key>
<string>MyApp needs access to save videos to your Photos library.</string>
<!-- ADD THIS: -->
<key>NSPhotoLibraryUsageDescription</key>
<string>MyApp needs access to your Photos library to organize videos into albums.</string>

cd mobile
flutter build macos --debug
open build/macos/Build/Products/Debug/MyApp.app

python3 -c "
import json, sys
with open(sys.argv[1]) as f:
    f.readline()  # skip header JSON line
    d = json.loads(f.read())
print('Signal:', d.get('exception', {}).get('signal'))
print('Namespace:', d.get('termination', {}).get('namespace'))
print('Details:', d.get('termination', {}).get('details'))
" ~/Library/Logs/DiagnosticReports/MyApp-*.ips

© divinevideo, MPL-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .agents/skills/macos-tcc-sigkill-missing-usage-description of divinevideo/divine-mobile.

Open the folder on GitHubat commit 4c622be