SKILL.md
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Xcode Build Engineering
Current Versions (Verify Before Use)
xcodebuild -version # Xcode version
xcrun simctl list devices # Available simulators
xcrun --show-sdk-path # SDK path
swift --version # Swift versionCheck Xcode release notes for the latest version.
Core Principles
- Command-line first. If you can't build from
xcodebuild, your CI will break. - Schemes are shared. Every scheme used in CI must be marked "Shared" in Xcode.
- DerivedData is disposable. Clean builds should succeed. Cache selectively.
- Simulators are ephemeral. Don't depend on simulator state between runs.
Build Commands
# Basic build
xcodebuild -workspace MyApp.xcworkspace -scheme MyApp -destination 'platform=iOS Simulator,name=iPhone 15' build
# Run tests
xcodebuild -workspace MyApp.xcworkspace -scheme MyApp -destination 'platform=iOS Simulator,name=iPhone 15' test
# Archive for distribution
xcodebuild -workspace MyApp.xcworkspace -scheme MyApp -configuration Release archive -archivePath build/MyApp.xcarchive
# Export IPA
xcodebuild -exportArchive -archivePath build/MyApp.xcarchive -exportPath build -exportOptionsPlist ExportOptions.plistCI Integration
# .github/workflows/ios.yml
- uses: maxim-lobanov/setup-xcode@v1
with:
xcode-version: latest-stable
- run: xcodebuild -workspace MyApp.xcworkspace -scheme MyApp -destination 'platform=iOS Simulator,name=iPhone 15' testCommon Anti-Patterns
| Anti-Pattern | Why It's Wrong | Fix |
|---|---|---|
| Non-shared scheme in CI | CI can't find the scheme | Check "Shared" in Manage Schemes |
| Hardcoded simulator name | Breaks when new Xcode drops old simulators | Use xcrun simctl list dynamically |
| Signing in CI without match | Manual provisioning is fragile | Use fastlane match or Xcode Cloud |
| Committing DerivedData | Bloated repo, conflicts | Add to .gitignore |
No -derivedDataPath |
Pollutes default location, cache issues | Explicit path in CI |
Validation Checklist
- Build succeeds with clean DerivedData
- Tests pass on CI simulator
- All schemes used in CI are shared
-
-derivedDataPathset explicitly in CI - Code signing works in CI (manual or automatic)
- Archive + export tested before release
Official Resources
- xcodebuild man page
- Xcode CLI docs
- fastlane for signing and distribution automation