macOS Signing Inspector

Before invoking Apple-only binaries, confirm the execution context is macOS. From Windows or Linux, run those steps in a Mac SSH project or through an already configured remote transport; do not retry missing Apple binaries locally.

Quick Start

Use this skill when the failure smells like codesigning rather than compilation: launch refusal, missing entitlement, invalid signature, sandbox mismatch, hardened runtime confusion, or trust-policy rejection.

When the goal is packaging or notarization rather than signature diagnosis, hand off to the project's established distribution workflow. This skill does not submit, poll, or staple notarization jobs.

Workflow

1. Inspect the bundle or binary.

   • Locate the .app or executable.
   • Identify the main binary inside Contents/MacOS/.

2. Read signing details.

   • Use codesign -dvvv --entitlements :- <path>.
   • Use spctl -a -vv <path> when Gatekeeper behavior matters.
   • Use plutil -p for entitlements or Info.plist inspection.

3. Classify the failure.

   • Unsigned or ad hoc signed
   • Wrong identity
   • Entitlement mismatch
   • Hardened runtime issue
   • App Sandbox issue
   • Nested code signing issue
   • Distribution/notarization prerequisite issue

4. Explain the minimum fix path.

   • Say exactly what is wrong.
   • Show the shortest set of validation or repair commands.
   • Distinguish local development problems from distribution problems.

Useful Commands

• codesign -dvvv --entitlements :- <app-or-binary>
• spctl -a -vv <app-or-binary>
• security find-identity -p codesigning -v
• plutil -p <path-to-entitlements-or-plist>

Guardrails

• Never invent missing entitlements.
• Do not conflate notarization with local debug signing.
• If the real issue is a build setting or provisioning profile, say so directly.

Output Expectations

Provide:

• what artifact was inspected
• what signing state it is in
• the exact failure class
• the minimum fix or validation sequence

Resources

• references/binary-tools.md — Mach-O inspection (nm, otool, llvm-objdump, dsymutil), .pkg packaging (pkgbuild, productbuild), and raw notarytool command forms.