[Android] ReactRootProjectPlugin drops :app:preBuild -> library preBuild dependency under --configure-on-demand, breaking codegen before CMake

Description

ReactRootProjectPlugin makes :app:preBuild depend on every library's preBuild so that library codegen runs before the app's CMake configure:

project.gradle.projectsEvaluated {
  val appProject = project.rootProject.subprojects.find { it.name == "app" }
  val appPreBuild = appProject?.tasks?.findByName("preBuild")
  if (appPreBuild != null) {
    val otherPreBuildTasks =
        project.rootProject.subprojects
            .filter { it != appProject }
            .mapNotNull { it.tasks.findByName("preBuild") }
    appPreBuild.dependsOn(otherPreBuildTasks)
  }
}

When Gradle runs with --configure-on-demand (Expo CLI passes it unconditionally in expo run:android), a library project that has not been evaluated by the time projectsEvaluated fires has no preBuild task yet, so findByName returns null and the dependency is silently dropped. The app's configureCMake<Variant> then runs before that library's generateCodegenArtifactsFromSchema, and the autolinking CMake file fails with:

CMake Error at android/app/build/generated/autolinking/src/main/jni/Android-autolinking.cmake:19 (add_subdirectory):
  add_subdirectory given source
  ".../node_modules/react-native-sherpa-onnx/android/build/generated/source/codegen/jni/"
  which is not an existing directory.
CMake Error at .../ReactAndroid/cmake-utils/ReactNative-application.cmake:97 (target_link_libraries):
  Cannot specify link libraries for target "react_codegen_SherpaOnnxSpec"
  which is not built by this project.

Which libraries are affected depends on evaluation order, so it looks flaky per project. In my project @stripe/stripe-react-native (also a codegen TurboModule library) happened to be evaluated in time and worked, while react-native-sherpa-onnx was not. The same failure was reported independently against that library (XDcobra/react-native-sherpa-onnx#63) and closed as not reproducible, which fits an ordering-dependent bug.

Running the identical build without --configure-on-demand (./gradlew :app:assembleDebug -PreactNativeArchitectures=arm64-v8a) succeeds; the task log shows :react-native-sherpa-onnx:generateCodegenArtifactsFromSchema → :app:preBuild → :app:configureCMakeDebug[arm64-v8a].

Workaround (verified): in the app's build.gradle, add an explicit task-path dependency, which forces on-demand configuration of that project:

preBuild.dependsOn(':react-native-sherpa-onnx:preBuild')

A robust fix would be to wire the dependency per subproject as each one is evaluated (e.g. subproject.afterEvaluate { appPreBuild.dependsOn(subproject.tasks.named("preBuild")) }, or dependsOn("${subproject.path}:preBuild") by task path) instead of snapshotting subprojects at projectsEvaluated.

Steps to reproduce

1. npx create-expo-app repro && cd repro
2. npx expo install react-native-sherpa-onnx @dr.pogodin/react-native-fs (any third-party library with codegenConfig and a JNI target that Gradle happens to evaluate late)
3. npx expo run:android (Expo CLI runs Gradle with --configure-on-demand)
4. Build fails in :app:configureCMakeDebug[<abi>] as above.
5. cd android && ./gradlew :app:assembleDebug succeeds.

React Native Version

0.86.0

Affected Platforms

Build - Android

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

System:
  OS: macOS 26.6.2
  CPU: (14) arm64 Apple M4 Pro
Binaries:
  Node: 24.12.0
  npm: 11.6.2
  Watchman: Not Found
Managers:
  CocoaPods: 1.17.0
IDEs:
  Android Studio: 2025.3
  Xcode: 26.2/17C52
Languages:
  Java: 17.0.12
Expo SDK 57 (expo 57.0.8), Gradle 9.3.1, AGP as shipped with RN 0.86.0, NDK 27.1.12297006, CMake 3.22.1

Stacktrace or Logs

> Task :stripe_stripe-react-native:generateCodegenArtifactsFromSchema
> Task :app:preBuild
...
> Task :react-native-sherpa-onnx:downloadNativeLibsIfNeeded
> Task :app:configureCMakeDebug[arm64-v8a] FAILED
(no :react-native-sherpa-onnx:generateCodegenArtifactsFromSchema before the failure)

Execution failed for task ':app:configureCMakeDebug[arm64-v8a]'.
> [CXX1429] error when building with cmake using .../ReactAndroid/cmake-utils/default-app-setup/CMakeLists.txt
  CMake Error at .../Android-autolinking.cmake:19 (add_subdirectory):
    add_subdirectory given source ".../react-native-sherpa-onnx/android/build/generated/source/codegen/jni/" which is not an existing directory.

MANDATORY Reproducer

Steps above (create-expo-app + react-native-sherpa-onnx + expo run:android). The failure depends on Gradle's on-demand evaluation order, so the library that gets skipped may differ by project.

Screenshots and Videos

N/A

Bắt đầu bằng cách xác định ReactRootProjectPlugin và theo dõi cách projectsEvaluated phát hiện các tác vụ preBuild của thư viện. Tái hiện bằng các bước bắt buộc với Expo và react-native-sherpa-onnx, sau đó so sánh thứ tự tác vụ Gradle khi dùng --configure-on-demand và khi chạy thông thường. Được coi là hoàn tất khi codegen của thư viện chạy trước app configureCMake và quá trình tạo CMake cho autolinking thành công.