SPM autolinking hardcodes iOS 15, so libraries whose Package.swift requires iOS 16+ can't be autolinked #58515

Description

scripts/spm/generate-spm-autolinking.js writes the top-level Autolinked package with a literal minimum platform (line 1072 in 0.87.1):

let package = Package(
    name: "Autolinked",
    platforms: [.iOS(.v15)],

Its AutolinkedAggregate target depends on the product of every autolinked library. SwiftPM doesn't let a target depend on a product whose package declares a higher minimum platform, so a self-managed library whose Package.swift declares .iOS(.v16) or later fails package resolution. That happens even when the app's own deployment target is 16.0 or higher. The library can't declare iOS 15 instead when its own dependencies need iOS 16, because SwiftPM applies the same check on that edge.

The same literal appears in two more places, which a fix should cover too:

• the per-dependency packages synthesized for podspec-based libraries (generate-spm-autolinking.js, line 1220)
• the manifests npx react-native spm scaffold writes (scaffold-package-swift.js, line 769)

Suggested fix, in order of preference, instead of the literal:

1. The highest .iOS(...) declared by an autolinked self-managed package. The aggregate has to be at least that, and the app target must already be at least that to link the library.
2. The app target's IPHONEOS_DEPLOYMENT_TARGET, read from the .xcodeproj the injector already edits.
3. An explicit spm.minimumIosVersion in the app's react-native.config.js.

Workaround, applied with patch-package:

--- a/node_modules/react-native/scripts/spm/generate-spm-autolinking.js
+++ b/node_modules/react-native/scripts/spm/generate-spm-autolinking.js
@@ -1069,7 +1069,7 @@
 
 ${guardBlock}let package = Package(
     name: "${AUTOLINKED_PACKAGE_NAME}",
-    platforms: [.iOS(.v15)],
+    platforms: [.iOS(.v16)],
     products: [
         .library(name: "${AUTOLINKED_PACKAGE_NAME}", targets: ["AutolinkedAggregate"]),
     ],

Steps to reproduce

1. Create a React Native 0.87.1 app and migrate it to SPM with npx react-native spm.
2. Add a native module that ships its own Package.swift declaring platforms: [.iOS(.v16)].
3. Raise the app target's IPHONEOS_DEPLOYMENT_TARGET to 16.0.
4. Run npx react-native spm update and build.

Expected: the packages resolve, since the app and the library both target iOS 16.
Actual: resolution fails with the error below.

React Native Version

0.87.1

Affected Platforms

Build - MacOS, Runtime - iOS

Output of npx @react-native-community/cli info

System:
  OS: macOS 26.7
  CPU: (16) arm64 Apple M4 Max
  Memory: 17.97 GB / 128.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.19.0
    path: /usr/local/bin/node
  Yarn:
    version: 4.11.0
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.9.3
    path: /usr/local/bin/npm
  Watchman:
    version: 2025.11.10.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: ~/.gem/ruby/3.4.0/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.2
      - iOS 26.2
      - macOS 26.2
      - tvOS 26.2
      - visionOS 26.2
      - watchOS 26.2
  Android SDK:
    API Levels:
      - "36"
      - "37"
    Build Tools:
      - 35.0.0
      - 36.0.0
    System Images:
      - android-35 | Pre-Release 16 KB Page Size Google APIs ARM 64 v8a
      - android-36 | Google Play ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: Not Found
  Xcode:
    version: 26.2/17C52
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.18
    path: /usr/bin/javac
  Ruby:
    version: 3.4.7
    path: ~/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.2.0
    wanted: 20.2.0
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.87.1
    wanted: 0.87.1
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Stacktrace or Logs

error: The package product 'Heracross' requires minimum platform version 16.0 for the iOS platform,
but this target supports 15.0 (in target 'AutolinkedAggregate' from project 'Autolinked')

MANDATORY Reproducer

https://github.com/bstillitano/rn-spm-ios16-repro

Built from the reproducer template (0.87.1): migrated to SPM, deployment target 16.0, and one stub library whose ios/Package.swift declares .iOS(.v16). Its iOS CI job fails with the error above; applying the one-line workaround makes the same build succeed.

Screenshots and Videos

None.