Fixing “Direct local .aar file dependencies are not supported…” using a Local Maven Repository(Gradle 8)

Stop fighting flatDir { … } and let your AAR behave like a first-class Maven artifact.

Android Gradle Plugin 8 throws this build-time error whenever a library module tries to embed a raw .aar inside another AAR:

Execution failed for task ':master:bundleDebugLocalLintAar'.
> Direct local .aar file dependencies are not supported when building an AAR …

Below is a step-by-step guide—with copy-paste code—to convert that raw file into a miniature, in-project Maven repository and wire every module to it via Gradle 8’s dependencyResolutionManagement.

The example uses an imaginary Connector 1.0.0 AAR; substitute your own library name or version as needed.

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Project baseline

AarTestApp/
├── master/                 # → Android library you package as an AAR
│   └── build.gradle.kts
├── app/                    # → Demo app that depends on :master
├── libs/
│   └── Connector-1.0.0.aar # ← raw AAR causing the build to fail
└── settings.gradle.kts

---

1 Create a “publisher” module

• Move the AAR into its own folder and make that folder a Gradle project:

mkdir -p libs/connector_publisher 
mv libs/Connector-1.0.0.aar libs/connector_publisher/

• Register the module in settings.gradle.kts:

include(":connector_publisher") 
project(":connector_publisher").projectDir = file("libs/connector_publisher")

• Add a build.gradle.kts inside libs/connector_publisher:

plugins { id("maven-publish") }

val connectorAar = file("Connector-1.0.0.aar")

publishing {
    publications {
        create<MavenPublication>("connector") {
            groupId = "com.example.connector"
            artifactId = "connector"
            version = "1.0.0"
            artifact(connectorAar)
        }
    }
    repositories {
         maven {
            name = "localAkamaiRepo"          
            url  = uri("${rootProject.rootDir}/local-maven-repo")
        }        
        // mavenLocal()
    }
}

This module doesn’t compile code; it simply tells Gradle “publish that file as a Maven artifact.”

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2 Publish once

./gradlew :connector_publisher:publishConnectorPublicationToLocalMavenRepoRepository

You should now see:

local-maven-repo/
└─ com/example/connector/connector/1.0.0/
   ├─ connector-1.0.0.aar
   └─ connector-1.0.0.pom

---

3 Tell all modules where that repo lives

(Gradle 8 syntax)

Open settings.gradle.kts and wire the repo once at the top:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()

        // ⭐ local repository for the published AAR
        maven { url = uri(rootDir.resolve("local-maven-repo")) }

        // mavenLocal()   // uncomment if you also published to ~/.m2
    }
}

---

4 Consume the library like any other Maven artifact

master/build.gradle.kts

dependencies {
    // expose to consumers? use api(); otherwise implementation()
    api("com.example.connector:connector:1.0.0")
}

Important: remove any old files("…/Connector-1.0.0.aar") or flatDir { … } lines—they’re no longer needed.

---

5 Build & profit!

./gradlew clean :app:assembleDebug

AGP now:

1. Finds com.example.connector:connector:1.0.0 in your local repo.
2. Merges its classes/resources into the master AAR.
3. Packages the master AAR into your app APK/AAB.

No more “direct local .aar dependencies” errors. 🎉

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Wrap-up

By turning your standalone .aar into a proper Maven artifact and pointing Gradle 8 at a local repository, you:

• Eliminate AGP’s AAR-within-AAR restriction.
• Keep a clear audit trail of library versions.
• Remove brittle flatDir hacks from your builds.

Happy (error-free) coding!