react-native-xcode27

Build and launch React Native and Expo apps with Xcode 27. Install it and rebuild. No code changes.

It fixes the errors that stop an app built with Xcode 27.

The build fails in a pod such as react-native-svg or async-storage:

The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 12.4, but the range of supported deployment target versions is 15.0 to 27.0.x. (in target 'RNSVG-RNSVGFilters' from project 'Pods')

Device builds say The iOS deployment target, and the pod, version and target vary.

With React Native before 0.83.5 built from source, the fmt pod fails to compile, for example:

include/fmt/format-inl.h:59:24: error: call to consteval function 'fmt::basic_format_string<char, fmt::basic_string_view<char> &, const char (&)[3]>::basic_format_string<FMT_COMPILE_STRING, 0>' is not a constant expression

The app closes as soon as it opens, and the log shows:

Application failed to launch: UIScene life cycle is required for apps built with this SDK. See "Transitioning to the UIKit scene-based life cycle" in the UIKit documentation for more information on migration.

The app closes at launch on iOS 16 and 17 only, on React Native 0.87 or later, when it uses a pod that calls C++ from Swift, such as react-native-nitro-modules (behind react-native-mmkv 4 and VisionCamera 5):

Termination Reason: Namespace DYLD, Code 4, Symbol missing
Symbol not found: __ZNSt13exception_ptr31__from_native_exception_pointerEPv

Install

React Native:

npm install react-native-xcode27
cd ios && pod install

Expo, in a development build or an EAS build:

npx expo install react-native-xcode27

Then build the app again. Autolinking adds the pod. There is no config plugin, and nothing to call from JavaScript. Run pod install with the Xcode you build with, because the build fix reads that Xcode's SDK.

Why Xcode 27 breaks the build

Xcode 27 turns an iOS deployment target below 15.0 from a warning into an error. React Native's react_native_post_install raises each pod's library target to React Native's minimum, but not the resource bundles pods declare, such as react-native-svg's RNSVGFilters and async-storage's privacy manifest bundle. Those keep the older minimum from their podspec, and Xcode refuses them.

React Native fixed this on its main branch on 2026-09-28 (react/react-native#58687), and it is not in a release yet. Expo fixed it in expo-modules-autolinking 57.0.5, which comes with SDK 57. react-native-svg merged its own fix (software-mansion/react-native-svg#3022), but 15.15.5, the latest release, still declares iOS 12.4.

fmt 11 fails to compile as C++20 with the Apple Clang in Xcode 26.4 and later, and React Native pinned fmt 11.0.2 until 0.83.5 (react/react-native#55601). The error comes from fmt's headers, so any C++20 pod that includes them fails too, not only fmt. The usual workaround is a Podfile edit that turns consteval off in fmt's base.h.

Why Xcode 27 breaks iOS 16 and 17

With Xcode's explicitly built Swift modules, Swift code that calls C++ through C++ interop (SWIFT_OBJC_INTEROP_MODE = objcxx) gets libc++'s iOS 18 implementation of std::make_exception_ptr even when the app supports earlier iOS. The object then references __cxa_init_primary_exception and std::exception_ptr::__from_native_exception_pointer, which iOS 17 and earlier don't have, so dyld refuses to start the app there. Built with implicit modules, the same code doesn't. React Native turned explicit modules off whenever it used its precompiled binaries, the default from 0.84 to 0.86. 0.87 removed that, so every pod now builds with explicit modules.

The crash was reported in react-native-nitro-modules (margelo/nitro#1652, on the iOS 17.5 simulator); its fixes (#1666, and the maintainers' #1675) are not merged, and 0.37.1, the latest release, still references both symbols.

Why Xcode 27 breaks the launch

Apple's UIKit documentation says apps built with the iOS 27 SDK "must adopt the scene-based life cycle or they fail to launch" (Transitioning to the UIKit scene-based life cycle). React Native's templates create their window in application:didFinishLaunchingWithOptions: and declare no scene. React Native adds scene support in 0.88 (react/react-native#57700, #57717), which is at 0.88.0-rc.3. Expo SDK 56 and earlier have none. SDK 57 ships an opt-in scene delegate, and SDK 58's templates use it.

What it does

At pod install:

• After your Podfile's own post_install has run, it raises every Pods target whose iOS deployment target is below the minimum of the active Xcode's SDK (15.0 in Xcode 27) to your app's deployment target. It prints each change, for example [react-native-xcode27] RNSVG-RNSVGFilters: iOS 12.4 -> 15.1. Targets the SDK accepts are left alone, and nothing is raised above your app's own deployment target. Xcode 26's iOS SDK accepts 12.0 and later, so there it normally changes nothing.
• If the fmt pod is older than 12.1, it turns consteval off for Apple Clang in the pod's copy of fmt/base.h, the same change as the usual Podfile workaround, so every pod that includes fmt compiles, and compiles the fmt pod itself as C++17. It prints [react-native-xcode27] fmt 11.0.2: consteval off in fmt/base.h.
• If the app supports iOS before 18, it turns Swift explicit modules off for the pods that use C++ interop, and prints [react-native-xcode27] NitroModules: Swift explicit modules off (C++ interop, app supports iOS 15.1). Pods without C++ interop, and apps that require iOS 18, are left alone.
• The podspec loads this from cocoapods/xcode27.rb by extending CocoaPods' Podfile post-install step. Your Podfile is not edited.

At launch, when built with the iOS 27 SDK:

• When UIKit sets the app delegate, and the app declares no scene (no UIApplicationSceneManifest in Info.plist, and no application:configurationForConnectingSceneSession:options:), it adds that method to the delegate's class, returning a configuration with its own scene delegate.
• The scene delegate puts the window your app delegate already created into the scene and makes it key and visible. If there is no window, it creates one and gives it to the app delegate.
• UIKit now sends links, user activities, quick actions and foreground and background transitions to the scene. It passes each one to the app delegate method that used to receive it, so RCTLinkingManager, Expo's app delegate subscribers and your own overrides keep working.
• A link that launches the app arrives with the scene, not in the launch options. It passes the link to application:openURL:options: as soon as the scene connects, which is where expo-linking records the link Expo Router starts from, and answers React Native's Linking.getInitialURL() with it when the launch options have none.
• If the app already declares a scene, it does nothing. With an SDK before iOS 27, this part compiles to nothing.

How it was checked

Xcode 27.0 (27A266a) on macOS 27.0, CocoaPods 1.16.2, iPhone 18 Pro simulator on iOS 27.0. CI adds CocoaPods 1.17.0 on GitHub's Xcode 27 image, and Xcode 16.4 and 26.6.

App	Without it	With it
React Native 0.86.3 with react-native-svg 15.15.5 and async-storage 3.1.1	Build fails on RNSVG-RNSVGFilters (12.4) and AsyncStorage-AsyncStorage_resources (13.0)	Builds and launches. Linking.getInitialURL() returns the link that launched the app
Expo SDK 56, default template with Expo Router and react-native-svg 15.15.4	Build fails on RNSVG-RNSVGFilters	Builds and launches. A link that launches the app opens the linked route
Expo SDK 54 (React Native 0.81.5), blank template with react-native-svg 15.12.1	Build fails on RNSVG-RNSVGFilters	Builds and launches
React Native 0.81.5 built from source, community template with react-native-svg 15.12.1	Build fails on RNSVG-RNSVGFilters, and its fmt 11.0.2 pod fails to compile as C++20 (call to consteval function)	Builds
React Native 0.87.1 with react-native-mmkv 4.3.2 (react-native-nitro-modules 0.37.1)	Builds, but the app references __cxa_init_primary_exception and std::exception_ptr::__from_native_exception_pointer, which iOS 16 and 17 don't have	Builds and launches, and the app references neither
Test app with a pod whose library and resource bundle target iOS 12.4, a stand-in for fmt 11.0.2, and a C++20 pod that includes fmt	Build fails	Builds
Test app with a pod that calls C++ from Swift, the way react-native-nitro-modules does	References the two iOS 18-only functions	References neither. An app that requires iOS 18 is left alone
Minimal UIKit app on the app-based life cycle	Fails to launch	Launches. The window follows the scene into landscape. Links reach application:openURL:options: whether they launch the app or arrive while it runs, and the app delegate's foreground and background methods run as they did before
Apps that declare a scene, in code or in Info.plist		Launch with their own scene delegate. The launch fix stays out

The last four rows are automated: npm test builds those apps and checks them in the booted simulator, and CI runs it on GitHub's Xcode 27 image. In an app with 45 popular native libraries, pod install raised 14 resource bundles from 13 pods, including Google Mobile Ads, RevenueCat, SDWebImage, Lottie and react-native-image-picker.

Limits

• Tested in the simulator only, not yet on a device.
• The iOS 16 and 17 launch crash was not run here, because no iOS 17 simulator runtime was installed. What was checked is that the app no longer references the two functions; the crash itself is reported in margelo/nitro#1652.
• CocoaPods only. Swift Package Manager dependencies are not changed.
• One window. iPad multiwindow needs real scene support.
• Universal links, Handoff and home-screen quick actions go through the same forwarding as custom-scheme links, but were not tested.
• Other Xcode 27 problems are out of scope. For example, react-native run-ios from @react-native-community/cli before 20.2 can't find Xcode 27's Simulator app; upgrade the CLI or run from Xcode.
• It includes the launch fix from react-native-uiscene-bridge. Use one or the other.
• Not affiliated with Apple, Meta or Expo.

License

MIT