0.88.0-rc.0: React-Core-prebuilt tarball missing Headers/module.modulemap — build fails (module map file not found) #58562

Description

pod install succeeds but immediately warns, and the subsequent Xcode build fails outright, on a fresh install of react-native@0.88.0-rc.0 (via expo@58.0.0-preview.2, Expo SDK 58 preview) using the standard CocoaPods prebuilt-binary integration. This is a different, independent issue from #58561 (which is about 0.86.3's prebuilt binary having an ABI mismatch with Hermes) — this one fails to even compile.

pod install warning (printed before any build step runs)

[!] [Expo] Prebuilt React-Core-prebuilt is missing Headers/module.modulemap — skipping Expo module-map coverage.
If the build fails with a missing module map or -Wnon-modular-include, the installed prebuilt React does not
match React Native's CocoaPods scripts; install a tarball that ships ReactNativeHeaders via
RCT_TESTONLY_RNCORE_TARBALL_PATH.

Build failure

error: module map file '.../ios/Pods/React-Core-prebuilt/Headers/module.modulemap' not found (in target 'libwebp' from project 'Pods')

(repeated across every target that depends on the React-Core-prebuilt module map — libwebp and others)

Repro

1. Fresh Expo SDK 58 preview bare-workflow app (or any app pinning react-native@0.88.0-rc.0 via the standard CocoaPods prebuilt-binary integration).
2. pod install — note the Headers/module.modulemap warning above.
3. Build for iphonesimulator.
4. Build fails with the module-map error above; does not compile at all.

Environment

• react-native: 0.88.0-rc.0
• expo: 58.0.0-preview.2 (SDK 58 preview)
• Xcode: 27.0
• Platform: macOS, arm64 (Apple Silicon)

Additional note (not this bug, but encountered getting to this repro)

react-native-worklets and react-native-reanimated's published peer ranges (0.83 - 0.87, as of react-native-worklets@0.12.2 / react-native-reanimated@4.6.0) don't yet include 0.88.x — npm install requires --legacy-peer-deps to get past that. Separate concern, flagging in case it's useful context for release sequencing.

Expected behavior

The React-Core-prebuilt tarball fetched for 0.88.0-rc.0 should ship a complete Headers/ directory including module.modulemap, matching what React Native's own CocoaPods integration scripts expect — no missing-file build failure.