build-dmg

name	build-dmg
version	2.0.0
description	Build a distributable macOS DMG from an Xcode project via the bundled local helper — archive → export → package into one signed artifact. Resolves the project/workspace, scheme, team ID, and export options, regenerates the project first when `xcodegen` is detected, then runs `helpers/build-dmg.sh` from the project root instead of inlining xcodebuild. User-only workflow that touches code signing and provisioning: it never GUESSES the signing identity, never overwrites `ExportOptions.plist` without approval, and reports the built DMG path, version, and signing status. Use only when the user explicitly asks to build or package a DMG.
allowed-tools	["AskUserQuestion","Bash","Read","Write"]
disable-model-invocation	true
user-invocable	true
argument-hint	[project, workspace, or scheme hint]
arguments	["request"]
when_to_use	Use when the user explicitly asks to build a DMG, package a macOS app for distribution, or create a signed installer — "build a DMG", "package this Mac app", "create a distributable installer". Do NOT use proactively or to run ad-hoc xcodebuild commands; it drives code signing and export, so it is user-only and asks before guessing any signing or export input.
effort	high

This skill runs `xcodebuild archive` + `exportArchive` and packages the result into a DMG. It touches code signing, provisioning, and export options.

Non-negotiable rules:

1. Detect project/workspace, scheme, and team ID before building — never guess signing identity.
2. If multiple schemes exist, ask the user which one to build.
3. Do not auto-create or overwrite ExportOptions.plist without explicit approval — wrong export options produce unsigned or wrong-distribution builds.
4. Use the helper script (helpers/build-dmg.sh) from the project root. Do not inline xcodebuild commands.
5. If xcodegen is detected (project.yml present), run xcodegen generate before building.
6. Report the built DMG path, app version, and signing status clearly.

build-dmg

Inputs

• $request: Optional project, workspace, scheme, or signing hint

Goal

Produce a DMG build by:

• resolving the right Xcode target inputs
• running the bundled helper script from the project root
• reporting the resulting DMG path and any packaging blockers

Step 0: Detect the packaging inputs

Read the repo and resolve:

• app name
• scheme
• project or workspace path
• ExportOptions.plist location if it exists
• VERSION file if present
• whether project.yml indicates xcodegen
• team ID or signing hints if already present

If a required input is ambiguous, ask before building.

Success criteria: The build configuration is explicit before the helper runs.

Step 1: Confirm helper and working directory

The helper script lives next to this skill at:

• helpers/build-dmg.sh

Run it from the project root so it can use the current repository as the build context.

Success criteria: The correct helper path and project root are established.

Step 2: Build with explicit environment

Provide the required environment variables such as:

• APP_NAME
• SCHEME

Add optional variables only when the project actually needs them:

• PROJECT
• WORKSPACE
• INFO_PLIST
• EXPORT_OPTIONS
• TEAM_ID
• VERSION_FILE
• USE_XCODEGEN
• DMG_BACKGROUND

Success criteria: The helper has all required inputs and only the needed optional ones.

Step 3: Handle success or failure cleanly

On success, report:

• DMG output path
• app version and build number if available
• whether the VERSION file was changed

On failure:

• summarize the real error
• surface the relevant xcodebuild or export failure lines
• identify whether the blocker is signing, scheme selection, export options, or build failure

Success criteria: The user gets either a usable artifact path or a clear blocker summary.

Guardrails

• Do not run this skill proactively.
• Do not assume .claude-local helper paths; use the helper inside this skill directory.
• Do not auto-create or overwrite export options without approval.
• Do not hide signing failures behind generic "build failed" summaries.

Output Contract

Report:

1. resolved app/project/workspace/scheme inputs
2. whether the helper ran successfully
3. DMG path on success
4. version/build info if available
5. exact blocker category on failure