Solving the Infuriating “Unable to Generate Merged Native Libs Folder” Error in Android

Are you tired of encountering the frustrating “Unable to generate merged native libs folder” error in your Android project? You’re not alone! This error can be a real roadblock in your development journey, but fear not, dear developer, for we’ve got you covered.

What’s causing the error?

Before we dive into the solutions, let’s understand what’s causing this error. The “Unable to generate merged native libs folder” error typically occurs when there’s a conflict between the native libraries in your project. This can happen when you’re using multiple libraries that include native code, or when you’ve added a new library that’s causing a conflict with an existing one.

Common scenarios that lead to this error

• Using multiple libraries that include native code, such as Firebase, Realm, or Facebook SDK.
• Adding a new library that includes native code, which conflicts with an existing library.
• Upgrading or downgrading a library that includes native code.
• Changing the Android NDK version or the Gradle build tool.

Solution 1: Clean and rebuild your project

Sometimes, the simplest solution is the most effective one. Try cleaning and rebuilding your project to see if that resolves the issue.

1. In Android Studio, go to Build > Clean Project.
2. Then, go to Build > Rebuild Project.
3. If you’re using the command line, run the following commands:

   
         ./gradlew clean
         ./gradlew build
       

Solution 2: Check and resolve library conflicts

If cleaning and rebuilding doesn’t work, it’s time to investigate library conflicts.

Step 1: Identify conflicting libraries

Check your project’s build.gradle file and identify the libraries that include native code. Look for libraries that have similar functionality or are known to cause conflicts.

dependencies {
    implementation 'com.google.firebase:firebase-auth:21.0.1'
    implementation 'io.realm:realm-android:10.10.1'
    implementation 'com.facebook.android:facebook-android-sdk:12.1.0'
}

Step 2: Exclude conflicting libraries

Try excluding the native libraries from the conflicting libraries using the exclude keyword.

dependencies {
    implementation ('com.google.firebase:firebase-auth:21.0.1') {
        exclude group: 'com.google.android', module: 'android-tests'
    }
    implementation ('io.realm:realm-android:10.10.1') {
        exclude group: 'com.google.android', module: 'android-tests'
    }
    implementation ('com.facebook.android:facebook-android-sdk:12.1.0') {
        exclude group: 'com.google.android', module: 'android-tests'
    }
}

Step 3: Check and resolve version conflicts

Check the version of the native libraries and make sure they’re compatible with each other. You can use the android_native_libs plugin to check the native library versions.

android {
    ...
    defaultConfig {
        ...
        externalNativeBuild {
            ndkBuild {
                ...
            }
        }
    }
    buildTypes {
        release {
            ...
            externalNativeBuild {
                ndkBuild {
                    ...
                }
            }
        }
    }
}

android_native_libs {
    libraries {
        firebase {
            versions '21.0.1'
        }
        realm {
            versions '10.10.1'
        }
        facebook {
            versions '12.1.0'
        }
    }
}

Solution 3: Use the abiFilters attribute

The abiFilters attribute allows you to specify the ABIs (Application Binary Interfaces) that your app should support. This can help resolve conflicts between native libraries.

android {
    ...
    defaultConfig {
        ...
        ndk {
            abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
    }
    ...
}

Solution 4: Use the android.nlm plugin

The android.nlm plugin provides a more granular control over native library management.

plugins {
    id 'com.android.application'
    id 'android.nlm'
}

android {
    ...
    defaultConfig {
        ...
        externalNativeBuild {
            ndkBuild {
                ...
            }
        }
    }
    ...
}

android.nlm {
    libraries {
        firebase {
            artifact 'com.google.firebase:firebase-auth:21.0.1'
            abi 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
        realm {
            artifact 'io.realm:realm-android:10.10.1'
            abi 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
        facebook {
            artifact 'com.facebook.android:facebook-android-sdk:12.1.0'
            abi 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
    }
}

Solution 5: Disable native library compression

In some cases, disabling native library compression can resolve the issue.

android {
    ...
    buildTypes {
        release {
            ...
            ndk {
                compression 'none'
            }
        }
    }
}

Solution 6: Check the Android NDK version

Make sure you’re using a compatible version of the Android NDK.

android {
    ...
    defaultConfig {
        ...
        ndkVersion '21.0.6113669'
    }
}

Solution 7: Clean the .gradle directory

Sometimes, cleaning the .gradle directory can resolve the issue.

rm -rf ~/.gradle

Conclusion

The “Unable to generate merged native libs folder” error can be frustrating, but by following these solutions, you should be able to resolve the issue and get back to developing your app. Remember to clean and rebuild your project, check and resolve library conflicts, use the abiFilters attribute, try the android.nlm plugin, disable native library compression, check the Android NDK version, and clean the .gradle directory.

Solution	Description
Clean and rebuild project	Try cleaning and rebuilding your project to see if that resolves the issue.
Check and resolve library conflicts	Identify conflicting libraries and try excluding them or resolving version conflicts.
Use the abiFilters attribute	Specify the ABIs that your app should support to resolve conflicts between native libraries.
Use the android.nlm plugin	Use the android.nlm plugin to provide more granular control over native library management.
Disable native library compression	Try disabling native library compression to see if that resolves the issue.
Check the Android NDK version	Make sure you’re using a compatible version of the Android NDK.
Clean the .gradle directory	Clean the .gradle directory to resolve any Gradle-related issues.

We hope this article has helped you resolve the “Unable to generate merged native libs folder” error in your Android project. If you’ve tried all the solutions and still encounter the issue, please leave a comment below, and we’ll do our best to assist you.

Bonus Tip:

When working with native libraries, it’s essential to keep your project’s build.gradle file clean and organized. Avoid using wildcards (*) in your dependency declarations, and instead, specify the exact library versions. This can help prevent version conflicts and make it easier

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