What problem does it solve?
macOS developers frequently hit cryptic code signing, entitlement, hardened runtime, or notarization errors when building and distributing apps. This Skill inspects the failing app bundle or binary and explains the exact failure class plus the minimum steps needed to fix it, replacing guesswork with verifiable diagnostics.
Core Features & Use Cases
- Failure Inspection: Examines the app bundle, executable, signing info, and entitlements using verifiable commands like codesign -d, spctl, and plutil.
- Failure Classification: Distinguishes identity, provisioning, hardened runtime, sandboxing, and trust policy problems, and separates local development signing issues from distribution or notarization failures.
- Minimal Repair Plan: Outputs the smallest repair sequence or validation command instead of broad, risky changes.
- Use Case: Your notarized macOS app fails Gatekeeper checks after re-signing. Invoke the skill with the app path to identify whether the hardened runtime or an entitlement mismatch is the cause and get the exact fix commands.
Quick Start
Ask the assistant to run /fix-codesign-error on your app bundle, for example by saying: inspect MyApp.app with the fix-codesign-error skill and tell me why the signature is invalid.
