AAR packaging support for pure C++ TurboModules

[arcticfox1919]

Description:

Hi there! 👋

I've encountered an issue with AAR packaging when it comes to pure C++ TurboModules, and I'm hoping to get some guidance or see if this is a known limitation.

Environment

• React Native version: 0.76.5
• Platform: Android
• Build type: AAR packaging

Problem Description

The AAR packaging script appears to not support pure C++ TurboModules properly. When I include dependencies like react-native-fs-turbo, the generated AAR package doesn't contain the native dynamic libraries (.so files) that these modules produce.

Steps to Reproduce

1. Add a pure C++ TurboModule dependency (e.g., react-native-fs-turbo) to a React Native project
2. Build the project into an AAR package using the current packaging script
3. Integrate the AAR into an Android app project
4. Run the application

Expected Behavior

The AAR should include all necessary native libraries from pure C++ TurboModules, allowing the consuming app to function correctly.

Actual Behavior

The AAR is missing the native dynamic libraries from pure C++ TurboModules. When the consuming app tries to use these modules, it throws:

Exception in native call from JS
com.facebook.react.common.JavascriptException: EarlyJsError: TurboModuleRegistry.getEnforcing(...): 'PlatformConstants' could not be found. Verify that a module by this name is registered in the native binary., stack:
          invariant@2126:26
          getEnforcing@2818:28
          anonymous@2786:68
          loadModuleImplementation@267:14
          guardedLoadModule@175:38
          metroRequire@89:92
          anonymous@2764:76
          loadModuleImplementation@267:14
          guardedLoadModule@175:38
          metroRequire@89:92
          anonymous@2723:75

Additional Context

I've tested this with multiple pure C++ TurboModules and consistently get the same result. It seems like the packaging process might not be properly detecting or including the native artifacts generated by these modules.

Would it be possible to enhance the AAR packaging to better support pure C++ TurboModules? Or if there's a workaround I should be aware of, I'd greatly appreciate any guidance!

Thanks for your time and for all the great work on this project! 🙏

[whydidoo]

I have the same issue with react-native-mmkv.

[Clarkkkk]

Same here. Any solutions?

[hurali97]

Hey folks 👋

Thanks for raising this issue. We tested the AAR with libraries having c++ code like reanimated and did not face any such issue. Can I get more information on how you're generating AAR? Also let me know if you're using brownfield-gradle-plugin to help generate your AAR?

Also let me know, If you're following a procedure as explained here.

With this setup, we have tested on libraries like reanimated, mmkv, rnscreens and others.

[whydidoo]

Hey folks 👋

Thanks for raising this issue. We tested the AAR with libraries having c++ code like reanimated and did not face any such issue. Can I get more information on how you're generating AAR? Also let me know if you're using brownfield-gradle-plugin to help generate your AAR?

Also let me know, If you're following a procedure as explained here.

With this setup, we have tested on libraries like reanimated, mmkv, rnscreens and others.

Hi, I’ve been following the instructions from doc but I’m using only the version classpath("com.callstack.react:brownfield-gradle-plugin:0.3.0").

[hurali97]

Hey folks 👋

Thanks for raising this issue. We tested the AAR with libraries having c++ code like reanimated and did not face any such issue. Can I get more information on how you're generating AAR? Also let me know if you're using brownfield-gradle-plugin to help generate your AAR?

Also let me know, If you're following a procedure as explained here.

With this setup, we have tested on libraries like reanimated, mmkv, rnscreens and others.

Hi, I’ve been following the instructions from doc but I’m using only the version classpath("com.callstack.react:brownfield-gradle-plugin:0.3.0").

@whydidoo - Thanks for the confirmation. Can you also share your aar's build.gradle file?

[whydidoo]

Hey folks 👋
Thanks for raising this issue. We tested the AAR with libraries having c++ code like reanimated and did not face any such issue. Can I get more information on how you're generating AAR? Also let me know if you're using brownfield-gradle-plugin to help generate your AAR?
Also let me know, If you're following a procedure as explained here.
With this setup, we have tested on libraries like reanimated, mmkv, rnscreens and others.

Hi, I’ve been following the instructions from doc but I’m using only the version classpath("com.callstack.react:brownfield-gradle-plugin:0.3.0").

@whydidoo - Thanks for the confirmation. Can you also share your aar's build.gradle file?

@hurali97 yep, I've sent an invite to you in my private repo

[hurali97]

@whydidoo - Thanks I will check it out

[hurali97]

Hey folks 👋

For the reproduction, I tried the following steps:

• created a new RNEF project
• ran yarn android to make sure project works as is
• installed react-native-mmkv
• ran yarn android to make sure project works as is
• then I generated AAR and consumed it in a native Android App
• I was able to get the same crash related to TurboModuleRegistry.getEnforcing(...)

---

This happens because the .so file for react-native-mmkv are not being bundled into the AAR. If you manually copy this library from app/build/intermediates/stripped_native_libs/release|debug/ and paste those in libsRelease|libsDebug, re-generate the AAR, you should not face this crash. However, this is only a temporary fix to unblock yourself.

I will investigate this issue, hopefully in the current week.

[whydidoo]

@hurali97 thanks a lot

[arcticfox1919]

@hurali97
I've encountered two new issues:

1. When I add the dependency "react-native-vlc-media-player": "^1.0.89", the packaging command fails with the following error:

│  ERROR: [string/app_name] /Users/arcticfox/workspace/test/brownfield-test/aar_demo/android/rnapp/build/intermediates/exploded-aar/aar_demo/callstack_react-native-brownfield/unspecified/release/res/values/values.xml [string/app_name] /Users/arcticfox/workspace/test/brownfield-test/aar_demo/android/rnapp/build/intermediates/exploded-aar/aar_demo/react-native-vlc-media-player/unspecified/release/res/values/values.xml: Resource and asset merger: Duplicate resources
│  
│  
│  * What went wrong:
│  Execution failed for task ':rnapp:packageReleaseResources'.
│  > [string/app_name] /Users/arcticfox/workspace/test/brownfield-test/aar_demo/android/rnapp/build/intermediates/exploded-aar/aar_demo/callstack_react-native-brownfield/unspecified/release/res/values/values.xml     [string/app_name] /Users/arcticfox/workspace/test/brownfield-test/aar_demo/android/rnapp/build/intermediates/exploded-aar/aar_demo/react-native-vlc-media-player/unspecified/release/res/values/values.xml: Error: Duplicate resources
│
■  Failed to build the AAR. See the error above for details from Gradle.

2. When I only include the dependency "@react-native-community/blur": "4.4.1", the Android app crashes with:

A  Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0xf13e78c2a4 in tid 13406 (pool-2-thread-1), pid 13381 (t.rnapplication)
2025-08-05 19:14:50.472 13412-13412 DEBUG                   pid-13412                            A  *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
2025-08-05 19:14:50.472 13412-13412 DEBUG                   pid-13412                            A  Build fingerprint: 'google/sdk_gphone64_arm64/emu64a:15/AE3A.240806.043/12960925:userdebug/dev-keys'
2025-08-05 19:14:50.472 13412-13412 DEBUG                   pid-13412                            A  Revision: '0'
2025-08-05 19:14:50.472 13412-13412 DEBUG                   pid-13412                            A  ABI: 'arm64'
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  Timestamp: 2025-08-05 19:14:50.379905609+0800
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  Process uptime: 1s
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  Cmdline: com.test.rnapplication
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  pid: 13381, tid: 13406, name: pool-2-thread-1  >>> com.test.rnapplication <<<
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  uid: 10210
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  tagged_addr_ctrl: 0000000000000001 (PR_TAGGED_ADDR_ENABLE)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  pac_enabled_keys: 000000000000000f (PR_PAC_APIAKEY, PR_PAC_APIBKEY, PR_PAC_APDAKEY, PR_PAC_APDBKEY)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x000000f13e78c2a4
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x0  0000007853bf2978  x1  00000078eabb0818  x2  0000007853bf2410  x3  0000007853bf2420
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x4  0000007853bf2f90  x5  0000000000000004  x6  00000000b400007a  x7  0000007853bf3198
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x8  0000007853bf2978  x9  0000000000000000  x10 00000078eab9992c  x11 0000007853bf2958
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x12 0000000000000013  x13 00000078ef362658  x14 00000078ef3626d8  x15 00000078efa16d70
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x16 0000007850b9e598  x17 00000078503b331c  x18 0000007846904000  x19 0000007853bf2978
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x20 0000007853bf2f90  x21 0000007853bf2410  x22 0000007853bf2420  x23 0000007853bf8a80
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x24 00000078eabb07f8  x25 000000003f800000  x26 0000000000000007  x27 000000780011d9a0
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      x28 0000007853bf43e0  x29 0000007853bf0b20
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A      lr  0000007850a6e414  sp  0000007853bf0aa0  pc  00000078503b335c  pst 0000000060001000
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  120 total frames
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A  backtrace:
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #00 pc 0000000000b6b35c  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::Props::Props()+64) (BuildId: 91d42e503f48747e)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #01 pc 0000000001226410  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::YogaStylableProps::YogaStylableProps(facebook::react::PropsParserContext const&, facebook::react::YogaStylableProps const&, facebook::react::RawProps const&)+116) (BuildId: 91d42e503f48747e)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #02 pc 00000000011e2f70  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::BaseViewProps::BaseViewProps(facebook::react::PropsParserContext const&, facebook::react::BaseViewProps const&, facebook::react::RawProps const&)+108) (BuildId: 91d42e503f48747e)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #03 pc 0000000001232e14  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::HostPlatformViewProps::HostPlatformViewProps(facebook::react::PropsParserContext const&, facebook::react::HostPlatformViewProps const&, facebook::react::RawProps const&)+96) (BuildId: 91d42e503f48747e)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #04 pc 000000000003ee90  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libappmodules.so (offset 0x164000) (facebook::react::AndroidBlurViewProps::AndroidBlurViewProps(facebook::react::PropsParserContext const&, facebook::react::AndroidBlurViewProps const&, facebook::react::RawProps const&)+76) (BuildId: 1d51cb0c9a36356ddf9755bcda74255b641b5d18)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #05 pc 00000000000396b8  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libappmodules.so (offset 0x164000) (void facebook::react::RawPropsParser::prepare<facebook::react::AndroidBlurViewProps>()+1044) (BuildId: 1d51cb0c9a36356ddf9755bcda74255b641b5d18)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #06 pc 0000000000039278  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libappmodules.so (offset 0x164000) (std::__ndk1::unique_ptr<facebook::react::ComponentDescriptor const, std::__ndk1::default_delete<facebook::react::ComponentDescriptor const>> facebook::react::concreteComponentDescriptorConstructor<facebook::react::ConcreteComponentDescriptor<facebook::react::ConcreteViewShadowNode<&facebook::react::AndroidBlurViewComponentName.<char const at offset 0>, facebook::react::AndroidBlurViewProps, facebook::react::AndroidBlurViewEventEmitter, facebook::react::AndroidBlurViewState, false>>>(facebook::react::ComponentDescriptorParameters const&)+64) (BuildId: 1d51cb0c9a36356ddf9755bcda74255b641b5d18)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #07 pc 0000000000f2dca4  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::ComponentDescriptorRegistry::add(facebook::react::ComponentDescriptorProvider) const+140) (BuildId: 91d42e503f48747e)
2025-08-05 19:14:50.473 13412-13412 DEBUG                   pid-13412                            A        #08 pc 0000000000f288c0  /data/app/~~HS4mN6tpS1gZU-XH55Sx7Q==/com.test.rnapplication-iOnHKo6m0b2N5HW--loZGw==/base.apk!libreactnative.so (offset 0xc64000) (facebook::react::ComponentDescriptorProviderRegistry::createComponentDescriptorRegistry(facebook::react::ComponentDescriptorParameters const&) const+232) (BuildId: 91d42e503f48747e)

I'm strictly following the brownfield documentation at https://www.rnef.dev/docs/brownfield/android. To facilitate issue reproduction, I've created a repository at https://github.com/arcticfox1919/brownfield-test. In this repository, android_demo is an APK project for integrating the AAR package, while aar_demo is the project used to generate the AAR.

You can use this repository to reproduce the issues I've mentioned. Steps:

First, modify aar_demo/package.json and add the following dependencies one by one: "react-native-fs-turbo": "^0.3.6", "react-native-vlc-media-player": "^1.0.89", "@react-native-community/blur": "4.4.1"

Navigate to the aar_demo project and execute:

yarn 
cd android
./gradlew generateCodegenArtifactsFromSchema
yarn rnef package:aar --variant Release --module-name rnapp

Then copy the generated AAR package to the native Android project at android_demo/app/libs

Finally, run the android_demo project on an emulator.

[whydidoo]

@arcticfox1919

Try to paste it in your module for integration.

gradle.taskGraph.whenReady {
  tasks.forEach { task ->
    if (task.name.startsWith("merge") && task.name.contains("JniLibFolders")) {
      task.doFirst {
        println("🔧 Removing duplicate .so files before ${task.name}")

        val abis = listOf("arm64-v8a", "armeabi-v7a", "x86", "x86_64")

        abis.forEach { abi ->
          val files = project.fileTree("build/intermediates/exploded-aar") {
            include("**/jni/$abi/**")
          }.files

          val groupedByName = files.groupBy { it.name }

          groupedByName.forEach { (fileName, duplicates) ->
            if (duplicates.size > 1) {
              val toKeep = duplicates.first()
              val toDelete = duplicates.drop(1)
              println("ABI: $abi — keeping: ${toKeep.absolutePath}")
              toDelete.forEach { file ->
                if (file.delete()) {
                  println("ABI: $abi — deleted duplicate: ${file.absolutePath}")
                } else {
                  println("ABI: $abi — FAILED to delete: ${file.absolutePath}")
                }
              }
            }
          }
        }
      }
    }
  }
}

it works for me with NitroModules

[hurali97]

@arcticfox1919 - For the second crash with blur library, I think it's happening because you're generating a release variant aar and trying to consume in a debug variant android app. To make it work, select the build variant in android app to release and this crash shouldn't appear.

In RNEF docs, there is a publications block where we configure the variant aware AARs. Which means when you publish the AAR to maven local or central or another repository, it would contain both debug and release variant AAR.

[whydidoo]

@hurali97 Thanks for your support

[arcticfox1919]

@arcticfox1919

Try to paste it in your module for integration.

gradle.taskGraph.whenReady {
  tasks.forEach { task ->
    if (task.name.startsWith("merge") && task.name.contains("JniLibFolders")) {
      task.doFirst {
        println("🔧 Removing duplicate .so files before ${task.name}")

        val abis = listOf("arm64-v8a", "armeabi-v7a", "x86", "x86_64")

        abis.forEach { abi ->
          val files = project.fileTree("build/intermediates/exploded-aar") {
            include("**/jni/$abi/**")
          }.files

          val groupedByName = files.groupBy { it.name }

          groupedByName.forEach { (fileName, duplicates) ->
            if (duplicates.size > 1) {
              val toKeep = duplicates.first()
              val toDelete = duplicates.drop(1)
              println("ABI: $abi — keeping: ${toKeep.absolutePath}")
              toDelete.forEach { file ->
                if (file.delete()) {
                  println("ABI: $abi — deleted duplicate: ${file.absolutePath}")
                } else {
                  println("ABI: $abi — FAILED to delete: ${file.absolutePath}")
                }
              }
            }
          }
        }
      }
    }
  }
}

it works for me with NitroModules

@whydidoo
Thanks for the help, but that didn't work for me. Might be because I don't depend on NitroModules at runtime."

[arcticfox1919]

@arcticfox1919 - For the second crash with blur library, I think it's happening because you're generating a release variant aar and trying to consume in a debug variant android app. To make it work, select the build variant in android app to release and this crash shouldn't appear.

In RNEF docs, there is a publications block where we configure the variant aware AARs. Which means when you publish the AAR to maven local or central or another repository, it would contain both debug and release variant AAR.

@hurali97
Thank you very much for your reply! The crash issue has indeed been resolved, but I've encountered a new problem:

Process: com.test.rnapplication, PID: 19456
com.facebook.react.common.JavascriptException: Error: Exception in HostFunction: java.lang.NoClassDefFoundError: Failed resolution of: Leightbitlab/com/blurview/BlurView;, 
stack: anonymous@1:46240

The @react-native-community/blur package depends on a third-party library implementation 'com.github.Dimezis:BlurView:version-2.0.4', but the AAR package doesn't seem to bundle this dependency. When I manually add this dependency to the APK project, it resolves the issue.

I'm wondering if all third-party packages that React Native projects depend on need to be handled this way - i.e., manually adding their Android native library dependencies to the main APK project?

Additionally, regarding the dynamic library inclusion issue for Pure C++ TurboModules, I have a temporary local solution. I modified the RNSourceSets.kt file in the gradle plugin and used it locally:

val copyLibTask =
    project.tasks.register("copy${capitalisedBuildType}LibSources", Copy::class.java) {
        it.dependsOn(":$appProjectName:$codegenTaskName")
        it.dependsOn(":$appProjectName:strip${capitalisedBuildType}DebugSymbols")
        it.dependsOn(":$projectName:$codegenTaskName")

        it.from(
            "$strippedNativeLibsPath/${buildType.name}/$strippedDebugSymbolsPath",
        )
        it.into(project.rootProject.file("$projectName/libs$capitalisedBuildType"))
        it.include("**/libappmodules.so", "**/libreact_codegen_*.so")
    }

I believe the main issue is this line: it.include("**/libappmodules.so", "**/libreact_codegen_*.so"), which misses dynamic libraries from third-party Pure C++ TurboModules, since many third-party dynamic libraries don't use the libreact_codegen_ prefix in their naming.

Therefore, I modified this part to include all dynamic libraries except specified ones. The changes are as follows:

fun getLibrariesToExclude(project: Project): List<String> {
    val extension = project.extensions.findByType(Extension::class.java)
    
    if (extension == null) {
        return emptyList()
    }
    
    val excludedLibraries = extension.excludedLibraries
    
    if (excludedLibraries.isEmpty()) {
        return emptyList()
    }
    
    val formattedLibraries = excludedLibraries.map { libFileName ->
        val formattedName = formatLibraryFileName(libFileName.trim())
        formattedName
    }
    
    return formattedLibraries
}

val copyLibTask =
    project.tasks.register("copy${capitalisedBuildType}LibSources", Copy::class.java) {
        it.dependsOn(":$appProjectName:$codegenTaskName")
        it.dependsOn(":$appProjectName:strip${capitalisedBuildType}DebugSymbols")
        it.dependsOn(":$projectName:$codegenTaskName")

        it.from(
            "$strippedNativeLibsPath/${buildType.name}/$strippedDebugSymbolsPath",
        )
        it.into(project.rootProject.file("$projectName/libs$capitalisedBuildType"))
        
        val librariesToExclude = TurboConfigManager.getLibrariesToExclude(project)

        it.include("**/*.so")
        
        if (librariesToExclude.isNotEmpty()) {
            it.exclude(librariesToExclude)
        }
    }

Then configure in the AAR module's build.gradle.kts:

configure<com.callstack.react.brownfield.utils.Extension> {
    excludedLibraries = listOf(
        "libfbjni.so",
        "libhermestooling.so", 
        "libjsctooling.so",
        "libjsi.so",
        "libreactnative.so",
        "libhermes.so"
    )
}

Do you have any better suggestions for improvement?