How do I track down the cause of this duplicate class Exception?

Question

I'm building my first Android app in Android Studio and a little lost with this issue.

Here's my Module build.gradle:

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
    id 'com.google.devtools.ksp' version "1.7.21-1.0.8"
    id 'org.jetbrains.kotlin.plugin.serialization' version '1.7.20'
}

android {
    namespace 'com.myApp'
    compileSdk 33

    defaultConfig {
        applicationId "com.myApp"
        minSdk 24
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        vectorDrawables {
            useSupportLibrary true
        }
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    buildFeatures {
        compose true
    }
    composeOptions {
        kotlinCompilerExtensionVersion '1.3.2'
    }
    packagingOptions {
        resources {
            excludes += '/META-INF/{AL2.0,LGPL2.1}'
        }
    }
}

dependencies {

    implementation 'androidx.activity:activity-compose:1.6.1'
    implementation "androidx.compose.material:material:$compose_material_version"
    implementation "androidx.compose.ui:ui:$compose_ui_version"
    implementation "androidx.compose.ui:ui-tooling:$compose_ui_version"
    implementation "androidx.compose.ui:ui-tooling-preview:$compose_ui_version"
    implementation 'androidx.compose.material3:material3:1.0.1'
    implementation 'androidx.core:core-ktx:1.9.0'
    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.6.0'
    implementation 'androidx.lifecycle:lifecycle-viewmodel-compose:2.6.0'
    implementation "androidx.navigation:navigation-compose:2.5.3"
    // Room
    implementation "androidx.room:room-runtime:$room_version"
    testImplementation 'junit:junit:4.13.2'
    ksp "androidx.room:room-compiler:$room_version"
    implementation "androidx.room:room-ktx:$room_version"
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    // Retrofit
    implementation "com.squareup.retrofit2:retrofit:2.9.0"
    // Retrofit with Scalar Converter
    implementation "com.squareup.retrofit2:converter-scalars:2.9.0"
    // Retrofit with Kotlin serialization Converter
    implementation "com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter:0.8.0"
    implementation 'com.squareup.okhttp3:okhttp:5.0.0-alpha.11'

    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.0")
}

Here's the stack:

Duplicate class kotlin.collections.jdk8.CollectionsJDK8Kt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.internal.jdk7.JDK7PlatformImplementations found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.internal.jdk7.JDK7PlatformImplementations$ReflectSdkVersion found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.internal.jdk8.JDK8PlatformImplementations found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.internal.jdk8.JDK8PlatformImplementations$ReflectSdkVersion found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.io.path.DirectoryEntriesReader found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.ExperimentalPathApi found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.FileVisitorBuilder found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.FileVisitorBuilderImpl found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.FileVisitorImpl found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.LinkFollowing found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathNode found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathRelativizer found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathTreeWalk found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathTreeWalk$bfsIterator$1 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathTreeWalk$dfsIterator$1 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathTreeWalkKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathWalkOption found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathsKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathsKt__PathReadWriteKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.io.path.PathsKt__PathUtilsKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.jdk7.AutoCloseableKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk7-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.20)
Duplicate class kotlin.jvm.jdk8.JvmRepeatableKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.jvm.optionals.OptionalsKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.random.jdk8.PlatformThreadLocalRandom found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.streams.jdk8.StreamsKt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.streams.jdk8.StreamsKt$asSequence$$inlined$Sequence$1 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.streams.jdk8.StreamsKt$asSequence$$inlined$Sequence$2 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.streams.jdk8.StreamsKt$asSequence$$inlined$Sequence$3 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.streams.jdk8.StreamsKt$asSequence$$inlined$Sequence$4 found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.text.jdk8.RegexExtensionsJDK8Kt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)
Duplicate class kotlin.time.jdk8.DurationConversionsJDK8Kt found in modules kotlin-stdlib-1.8.10 (org.jetbrains.kotlin:kotlin-stdlib:1.8.10) and kotlin-stdlib-jdk8-1.7.20 (org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.20)

You have two different .jar versions configured into whatever it is that requires one of them, it's being told to load both when only one is required.! Remove one of those jars. — Samuel Marchant, Mar 15 '23 at 04:49
Could you please try to remove this line and see if it helps? implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.0") — zomega, Mar 17 '23 at 09:11
Thanks @zomega, I removed that but still have the same exception. — coder, Mar 17 '23 at 14:52

score 6 · Accepted Answer · answered Mar 17 '23 at 10:19

6

The reported conflict is between two versions of Kotlin standard library: kotlin-stdlib-1.8.10 and kotlin-stdlib-jdk8-1.7.201.

As suggested here, try and replace the oldest one with:

// Align versions of all Kotlin components
implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.8.0"))
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.8.0"

But: if you did not even include explicitly these dependencies, then excluding kotlin-stdlib-jdk8 might be enough.

As in this answer, add the following in build.gradle (:app)

configurations.implementation {
  exclude group: 'org.jetbrains.kotlin', module: 'kotlin-stdlib-jdk8'
}

answered Mar 17 '23 at 10:19

VonC

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In his gradle there is no kotlin-stdlib-jdk* – zomega Mar 17 '23 at 12:24
Thanks @VonC! Excluding kotlin-stdlib-jdk8 resolved my issue...but why was that necessary? – coder Mar 17 '23 at 15:02
1

@coder As noted by zomega, there is no `kotlin-stdlib-jdk*` in your declared direct dependencies. I suspect `kotlin-stdlib-jdk*` was imported indirectly, and excluding its indirect import helped, since `kotlin-stdlib-1.8.10` has already defined the same classes. – VonC Mar 17 '23 at 18:04

How do I track down the cause of this duplicate class Exception?

1 Answers1