[Shahroz16]

Refs MBL-2397

Stacked on #667 (Node 24 actions): base branch ci/node24-actions. Retarget to main after #667 merges.

Implements the 2026-10-21 decision: regular CI moves to Xcode 27 now; an Xcode 26 PR check stays only where it's cheap; separate Xcode 27 nightlies go once the regular jobs pass.

1. Regular iOS builds → Xcode 27

build-sample-app.yml is the only workflow that builds iOS on every PR and on main:

• runs-on: macos-26 → xcode-27, the runner the scene E2E lane already uses (GitHub-hosted public preview, [macOS] Xcode 27 is now available as a public preview actions/runner-images#14404). This covers every iOS sample build: PR verification (APN always, FCM when iOS paths change), signed distribution on main and ci:full, and the release sample apps after deploy.
• Pins Xcode 27.0 (XCODE_VERSION) through mobile-ci-tools setup-ios. 27.0 is the image default; 27.1 RC and 27.2 beta are also installed.
• Selects Xcode right after checkout. It used to run just before the final build, so the deep-link swiftc test and pod install ran on whatever the image defaulted to.
• Asserts the toolchain with report-toolchain (Xcode and iOS SDK major 27), like the scene lane.
• Adds timeout-minutes: 60 on execution. Builds take 20–35 minutes (measured on recent runs), and queue time doesn't count.
• Job names are unchanged. main has no required status checks, so nothing needs a ruleset update either way.

2. Xcode 26 PR check: none

None of this repo's existing checks is a cheap Xcode 26 check. The only iOS PR jobs are full sample-app builds (npm, pod install, Release simulator build): 20–35 minutes each on macOS.

I considered keeping the FCM PR build on Xcode 26 as a zero-extra-job check, and rejected it on Codex's advice. FCM adds MessagingPushFCM / CioFirebaseWrapper and Firebase code paths that APN doesn't compile. Now that Xcode 27 is the primary compiler, losing FCM-on-27 on PRs costs more than losing APN-on-26.

Known gap: after this, nothing in this repo compiles the wrapper with Xcode 26 / Swift 6.2. Customers shipping to the App Store still build with Xcode 26 until Apple requires Xcode 27. If that matters, the cheapest add-on would be a separate macos-26 job compiling only the CocoaPods customerio-reactnative target. It still needs npm and pod install, so it's not free.

3. Scene E2E nightly: kept as the only scheduled iOS validation job (unchanged)

react-native-scene-e2e.yml already runs on xcode-27. It isn't folded into regular CI because:

• It's too expensive for every PR. One run generates a fresh RN 0.88 template host, installs its pods, builds Release, and drives Maestro through warm, cold and declined notification flows plus ordinary links. That's about 25–40 minutes on the preview image, plus queueing (24 minutes on ci(e2e): stop pinning the scene E2E simulator model #668's last run).
• It's already in regular CI where it matters. react-native-scene-e2e-full.yml runs the same lane on PRs that touch scene-routing paths, or that carry ci:full.
• The nightly catches drift no PR touches. That's runner-image changes (like the iPhone 17 Pro removal) and new native SDK versions. ci(e2e): stop pinning the scene E2E simulator model #668's simulator fix comes first; this PR doesn't touch the scene workflows, so it doesn't trigger that lane.

It's the only scheduled iOS validation job (auto-update-native-sdks.yml has a schedule too, for SDK bump automation, unchanged).

4. Redundant after the move

Nothing; checked after the Xcode 27 jobs passed, so there's no cleanup commit. This repo has no Xcode 27-only nightly: the scene E2E nightly tests scene routing, not toolchain compatibility (section 3). The old late setup-ios step was moved, not duplicated.

Pre-existing, not changed here: the "Cache CocoaPods downloaded dependencies" step caches example/Pods, but pod install writes example/ios/Pods, so the cache never hits. That's a separate fix.

CI

All green (run 39535789047): 14 pass, 3 skipped by design (PR comment, scene lane, distribution).

Job	Runner / toolchain	Result
iOS APN sample app	xcode-27, image macos27 20261012.0260.1, macOS 27.0.1, Xcode 27.0 (27A266a), iOS SDK 27.0	✅ 21 min
iOS FCM sample app	same	✅ 18 min
Android APN sample app	ubuntu-latest	✅ 15 min

On the preview image these all worked: setup-xcode resolving 27.0, the Xcode 27 toolchain check, Homebrew sd/xcbeautify, Ruby 3.4 + bundler cache, pod install, and the deployment-target audit. Signed distribution (main / ci:full) hasn't run on Xcode 27 yet; it runs the same steps plus Fastlane gym and the Firebase upload.

Codex review

Approach consult:

• Codex advised moving both APN and FCM PR builds to 27 rather than splitting them across 26 and 27. Adopted.
• It advised selecting Xcode before any toolchain-dependent step, and asserting the Xcode and SDK majors. Adopted.
• It advised an execution timeout. Adopted.
• It advised keeping both scene workflows. Adopted.
• It also raised the dead Pods cache path. Noted above.

Adversarial review: no confirmed findings. Codex found the step order with the job's working-directory default fine, as well as the runs-on expression, env inside a step's with: and the unchanged job name.

• The timeout now also bounds Android (60 minutes); Android builds take 10–16 minutes, so that's harmless.
• Codex couldn't verify these from git alone: report-toolchain@main inputs (checked: expected-xcode-major / expected-ios-sdk-major exist), setup-xcode resolving 27.0, and Homebrew / Ruby 3.4 on the macOS 27 image. CI on this PR is the check for those.

🤖 Generated with Claude Code