Fix "InitializationProvider" Error in the AGP 9 Era 🚀

Hi fellow Android devs! 🤖

You’ve finished your app, everything works perfectly in Debug mode, and you’re finally ready to hit that "Release" button. But then… CRASH. 💥

You look at the logs and see this scary message: 


Fatal Exception: java.lang.RuntimeException: 
  Unable to get provider androidx.startup.InitializationProvider

Don't worry! You’re not alone, and your code isn't "broken." You've just run into a little disagreement between WorkManager and R8 (the code shrinker), especially if you're using the latest AGP 9 (Android Gradle Plugin).

Let’s fix it together in 3 minutes! ☕️

 

What’s happening under the hood? 🧐

When you set isMinifyEnabled = true for your release build, a smart tool called R8 starts cleaning up your code. It looks for anything "unused" and removes it to make your app tiny.

However, WorkManager (the tool that handles background tasks for things like AdMob or Firebase) has a little secret: it uses a class called WorkDatabase_Impl.

The problem? R8 doesn't see anyone "calling" this class in your code, so it thinks, "Hey, this is trash!" and throws it away. When your app starts, WorkManager looks for its database class, finds nothing, and—BOOM—the app crashes.

With AGP 9, R8 is stricter than ever, so we have to be very clear about what we want to keep.

You don't even need to update your library versions. Just follow these steps.

 

Step 1: Tell R8 to "Hands Off!" 🛑

Open your proguard-rules.pro file and add these lines. This tells the compiler: "I know it looks unused, but I need this! Please don't touch it."


# Keep the WorkManager internal database!
-keep class androidx.work.impl.WorkDatabase_Impl { *; }

# Also keep the "Worker" constructors so they can do their jobs
-keep class * extends androidx.work.ListenableWorker {
    <init>(android.content.Context, androidx.work.WorkerParameters);
}

 

Step 2: Give it a Fresh Start ✨

AGP 9 loves caching things. To make sure your new rules are applied:


Click Build > Clean Project.
Click Build > Rebuild Project.

 

Step 3: The "Magic" Re-install 📲

If your app tried to start and failed, it might have left some messy, half-finished files behind. Uninstall the app from your phone/emulator first, then install the new build. This ensures a 100% clean slate!

 

Wrapping Up 🎁

That’s it!

Your app should now be running smoothly even with isMinifyEnabled = true.

The AGP 9 era brings us faster and smaller apps, but it also means we have to be a bit more specific with our ProGuard/R8 rules.

Keep an eye on those "Impl" classes, and you'll be a release-build master in no time!

Happy coding! 💻✨

👉 【Android/AGP9対応】AdMob起因？WorkManagerとApp Startupで頻発するクラッシュをProGuard設定で解決する

Embracing AGP 9 and JDK 21: A Gradual Path to Android Build Optimization

As Android developers, major AGP (Android Gradle Plugin) updates are always significant. AGP 9 in particular promises a stricter, faster build environment, moving away from ambiguous configurations.

Instead of waiting for its full release and then scrambling to fix issues, why not start preparing your project now, gradually aligning it with "AGP 9 standards" through your gradle.properties file?

 

🤔 Why JDK 21 and AGP 9 Now? (The Ultimate Synergy)

When transitioning to AGP 9, updating to JDK 21 isn't just a "requirement"; it's a powerful "booster" that dramatically enhances your development experience.

  • Performance Synchronization: JDK 21's improved resource management, including features like Virtual Threads, allows Gradle to fully leverage its parallel build capabilities, leading to more stable and efficient builds.
  • Language Specification Alignment: By targeting Java 21, you bridge potential gaps in type inference and bytecode generation in mixed Java/Kotlin projects, especially as Kotlin 2.x gains traction.
  • Precision R8 Optimization: AGP 9 is optimized to parse and transform class files generated by JDK 21. This means that even with stricter settings, R8 can more accurately understand modern code structures, reducing the need for excessive keep rules while safely shrinking code.

This combination offers the kind of seamless experience you get from pairing the latest OS with the latest CPU.

 

🤔 Prepare with gradle.properties: 10 Flags to Enable Today

The strategy is simple: enable one flag at a time, fix any errors that arise, and then move to the next. This iterative approach is the most reliable way to prepare for AGP 9.

1. Structure Enforcement (Clean Up Your Project)

  • android.uniquePackageNames=true: Prevents duplicate package names across modules, eliminating resource conflicts.
  • android.usesSdkInManifest.disallowed=true: Enforces placing minSdk, targetSdk, etc., in build.gradle instead of AndroidManifest.xml.
  • android.defaults.buildfeatures.resvalues=true: Explicitly controls the generation of resValue entries.

2. Build Speed Enhancements

  • android.enableAppCompileTimeRClass=true: Uses lightweight R classes during app compilation, significantly improving build times for large projects.
  • android.sdk.defaultTargetSdkToCompileSdkIfUnset=true: Automatically sets targetSdk to compileSdk if unspecified, preventing inconsistent behavior.
  • android.dependency.useConstraints=true: Utilizes Gradle's "Constraints" feature for dependency resolution, making library version management more robust.

3. Aggressive R8 / Optimization Settings (The Biggest Hurdle)

  • android.r8.strictFullModeForKeepRules=true: Enables R8's Full Mode. This maximizes optimization but requires precise keep rules for code that relies on reflection, potentially leading to crashes if not handled correctly.
  • android.r8.optimizedResourceShrinking=true: Employs a more advanced algorithm for removing unused resources, leading to smaller app sizes.

4. Next-Gen Defaults

  • android.builtInKotlin=true: Prioritizes AGP's built-in Kotlin support.
  • android.newDsl=false: Use this to maintain the current DSL while preparing for future changes.

 

🤔 Conclusion: One Flag at a Time for a Smoother Future

The AGP 9 update is akin to a major cleanup. Attempting it all at once can be overwhelming, but tackling it gradually makes it incredibly rewarding.

Why not start with android.uniquePackageNames=true? With each flag you enable, your project will move closer to a more modern, robust, and efficient build environment.

👉 AGP 9.0 移行ガイド：新旧コード比較で見るモダンビルド設定

Hilt Build Error on Kotlin 2.3.0: Provided Metadata instance has version 2.3.0 — Causes and Fixes Explained


error: [Hilt] Provided Metadata instance has version 2.3.0, while maximum supported version is 2.2.0.

This article explains the background of this error and introduces a new solution available since Dagger 2.57.

 

🤔 🧑🏻‍💻 1. Cause of the Error

This error occurs because kotlin-metadata-jvm, a library used internally by Dagger/Hilt, cannot understand the newer Kotlin metadata format (version 2.3.0).

Shading (Inshading) explained:

  • Shading means that a dependency is relocated and bundled inside another library’s JAR.
  • In earlier Dagger versions, kotlin-metadata-jvm was shaded (hidden) inside Dagger itself.
  • As a result, developers could not override or update it, even if Kotlin introduced a new metadata version.
  • This tightly coupled Dagger’s compatibility to a specific Kotlin version and forced users to wait for a Dagger release.

 

🤔 🧑🏻‍💻 2. What Changed in Dagger 2.57

Starting from Dagger 2.57, kotlin-metadata-jvm is unshaded (no longer hidden).

This means:

  • The dependency is now resolved normally via Gradle
  • Developers can explicitly specify a newer version without waiting for a Dagger update

This architectural change significantly improves Kotlin version agility.

 

🤔 🧑🏻‍💻 3. Solution: Explicitly Declare the Dependency

If you are using Kapt

Kapt runs through the Java compiler and is more sensitive to metadata incompatibility.


dependencies {
    // Add the latest metadata library to kapt
    kapt("org.jetbrains.kotlin:kotlin-metadata-jvm:2.3.0-Beta1")
}

If you are using KSP

KSP is directly integrated with the Kotlin compiler, so this error is less likely.

If needed, you can still specify it explicitly.


dependencies {
    // Add to ksp configuration
    ksp("org.jetbrains.kotlin:kotlin-metadata-jvm:2.3.0-Beta1")
}

Recommended: Force the version globally

If multiple modules are affected, this is the most reliable approach.


configurations.all {
    resolutionStrategy {
        force "org.jetbrains.kotlin:kotlin-metadata-jvm:2.3.0-Beta1"
    }
}

 

🤔 🧑🏻‍💻 4. Summary

  • If you are using Dagger 2.57 or later, you do not need to wait for a new Dagger release.
  • When the error appears, explicitly add the latest kotlin-metadata-jvm to your kapt or ksp configuration.
  • In general, migrating to KSP is recommended due to better compatibility and performance.
  • Developers who want to adopt the latest Kotlin features early should definitely apply this setup.

👉 Upgrade kotlin-metadata-jvm to support Kotlin 2.3.0 · Issue #5001 · google/dagger