AARs generated by the Android Multiplatform Plugin do not contain a .kotlin_module file in the classes.jar, which causes a failure to resolve extension functions in consuming libraries.

I can see there is an exclusion in packaging.resources.exclude that seems to match .kotlin_module files but removing the exclusion doesn't seem to work around the issue.

I was able to reproduce the issue by attempting to use an extension function from the simple project below.

When used as a project dependency the resolution succeeds, but when published to maven local and consumed from an AAR the extension function doesn't resolve. It works both ways when using the commented out android library plugin version.

import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
import org.jetbrains.kotlin.gradle.dsl.JvmTarget

plugins {
    alias(libs.plugins.kotlinMultiplatform)
//    alias(libs.plugins.androidLibrary)
    alias(libs.plugins.androidMultiplatform)
    id("maven-publish")
}

kotlin {
//    androidTarget {
//        publishLibraryVariants("release")
//        compilerOptions {
//            jvmTarget.set(JvmTarget.JVM_1_8)
//        }
//    }
    androidLibrary {
        namespace = "org.jetbrains.kotlinx.multiplatform.library.template"
        compileSdk = libs.versions.android.compileSdk.get().toInt()
        minSdk = libs.versions.android.minSdk.get().toInt()
        packaging.resources.excludes.remove("**/*.kotlin_metadata")
    }

    sourceSets {
        val commonMain by getting {
            dependencies {
                //put your multiplatform dependencies here
            }
        }
    }
}

version = "0.0.1"

//android {
//    namespace = "org.jetbrains.kotlinx.multiplatform.library.template"
//    compileSdk = libs.versions.android.compileSdk.get().toInt()
//    defaultConfig {
//        minSdk = libs.versions.android.minSdk.get().toInt()
//    }
//}

AGP Version: 8.6.0-beta01