Error with java8 and Kotlin - java-8

Question

I have an app where I'm using retrolambda so in the build.gradle I have
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
Everything is fine unless I add the support for Kotlin.
Adding the Kotlin plugin I get the following error:
Error:Error converting bytecode to dex:
Cause: Dex cannot parse version 52 byte code.
This is caused by library dependencies that have been compiled using Java 8 or above.
If you are using the 'java' gradle plugin in a library submodule add
targetCompatibility = '1.7'
sourceCompatibility = '1.7'
to that submodule's build.gradle file.
I have found many questions and answers similar to this one but non of the solutions apply in my case.
This is my build.gradle:
buildscript {
repositories {
maven { url 'https://maven.fabric.io/public' }
mavenCentral()
}
dependencies {
classpath 'me.tatarka:gradle-retrolambda:3.3.1'
classpath 'io.fabric.tools:gradle:1.+'
}
}
repositories {
// Required because retrolambda is on maven central
mavenCentral()
maven { url 'https://maven.fabric.io/public' }
maven { url 'https://maven.google.com' }
}
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'
apply plugin: 'realm-android'
apply plugin: 'com.neenbedankt.android-apt'
apply plugin: 'kotlin-android'
plugins {
id "me.tatarka.retrolambda" version "3.3.1"
}
android {
compileSdkVersion 25
buildToolsVersion '25.0.2'
compileOptions.incremental = false
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
defaultConfig {
multiDexEnabled true
applicationId "mypackage"
minSdkVersion 17
targetSdkVersion 25
versionCode 1
versionName "0.1"
vectorDrawables.useSupportLibrary = true
jackOptions {
enabled false
}
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
dexOptions {
preDexLibraries = false
javaMaxHeapSize "4g"
}
}
compileOptions {
incremental true
}
buildTypes {
release {
debuggable false
minifyEnabled true
zipAlignEnabled true
renderscriptDebuggable false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
signingConfig signingConfigs.release
}
debug {
debuggable true
signingConfig signingConfigs.debug
minifyEnabled false
versionNameSuffix "_dev"
}
}
}
def supportVersion = '25.3.1'
dependencies {
def daggerVer = 2.8
apt "com.google.dagger:dagger-compiler:$daggerVer"
compile "com.google.dagger:dagger:$daggerVer"
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:multidex:1.0.1'
compile "com.android.support:appcompat-v7:$supportVersion"
compile "com.android.support:design:$supportVersion"
compile "com.android.support:cardview-v7:$supportVersion"
compile "com.android.support:recyclerview-v7:$supportVersion"
compile "com.android.support:gridlayout-v7:$supportVersion"
compile "com.android.support:support-annotations:$supportVersion"
compile "com.android.support:preference-v7:$supportVersion"
compile "com.android.support:support-v4:$supportVersion"
compile "com.android.support:support-vector-drawable:$supportVersion"
compile "com.android.support:palette-v7:$supportVersion"
def firebase = '10.2.0'
compile "com.google.firebase:firebase-crash:$firebase"
compile "com.google.firebase:firebase-auth:$firebase"
compile 'com.firebaseui:firebase-ui-auth:1.2.0'
def rxbinding = '2.0.0'
compile "com.jakewharton.rxbinding2:rxbinding:$rxbinding"
compile "com.jakewharton.rxbinding2:rxbinding-support-v4:$rxbinding"
compile "com.jakewharton.rxbinding2:rxbinding-appcompat-v7:$rxbinding"
compile "com.jakewharton.rxbinding2:rxbinding-design:$rxbinding"
compile "com.jakewharton.rxbinding2:rxbinding-recyclerview-v7:$rxbinding"
compile "com.jakewharton.rxbinding2:rxbinding-leanback-v17:$rxbinding"
compile 'joda-time:joda-time:2.5'
compile 'com.ryanharter.auto.value:auto-value-parcel-adapter:0.2.5'
compile 'com.jakewharton.timber:timber:4.3.1'
compile 'com.github.bumptech.glide:glide:3.7.0'
compile 'com.github.clans:fab:1.6.4'
compile 'me.relex:circleindicator:1.2.2#aar'
compile 'com.github.paolorotolo:appintro:4.1.0'
//architecture
compile "android.arch.lifecycle:runtime:1.0.0-alpha1"
compile "android.arch.lifecycle:extensions:1.0.0-alpha1"
annotationProcessor "android.arch.lifecycle:compiler:1.0.0-alpha1"
def retrofit2 = '2.2.0'
def okhttp3 = '3.4.1'
compile "com.squareup.retrofit2:retrofit:$retrofit2"
compile "com.squareup.retrofit2:adapter-rxjava2:$retrofit2"
compile "com.squareup.retrofit2:converter-gson:$retrofit2"
compile "com.squareup.retrofit2:converter-scalars:$retrofit2"
compile "com.squareup.okhttp3:okhttp:$okhttp3"
compile "com.squareup.okhttp3:okhttp-urlconnection:$okhttp3"
compile "com.squareup.okhttp3:logging-interceptor:$okhttp3"
compile 'com.github.franmontiel:PersistentCookieJar:v1.0.1'
compile 'com.github.MFlisar:RxBus2:0.1'
def butter_knife = '8.4.0'
apt "com.jakewharton:butterknife-compiler:$butter_knife"
compile "com.jakewharton:butterknife:$butter_knife"
def leak_canary = '1.4'
debugCompile "com.squareup.leakcanary:leakcanary-android:$leak_canary"
releaseCompile "com.squareup.leakcanary:leakcanary-android-no-op:$leak_canary"
testCompile "com.squareup.leakcanary:leakcanary-android-no-op:$leak_canary"
apt 'com.gabrielittner.auto.value:auto-value-with:1.0.0'
apt 'com.google.auto.value:auto-value:1.2'
apt 'com.ryanharter.auto.value:auto-value-parcel:0.2.5'
apt 'com.ryanharter.auto.value:auto-value-gson:0.3.2-rc1'
provided 'javax.annotation:jsr250-api:1.0'
provided 'com.google.auto.value:auto-value:1.2'
compile 'com.braintreepayments.api:drop-in:3.0.6'
//other dependencies for testing
def hamcrestVersion = '1.3'
testCompile "org.hamcrest:hamcrest-core:$hamcrestVersion"
testCompile "org.hamcrest:hamcrest-library:$hamcrestVersion"
testCompile "org.hamcrest:hamcrest-integration:$hamcrestVersion"
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
testCompile 'org.mockito:mockito-core:1.10.19'
testCompile 'junit:junit:4.12'
compile('com.crashlytics.sdk.android:crashlytics:2.6.8#aar') {
transitive = true;
}
compile 'com.android.support.constraint:constraint-layout:1.0.2'
compile 'org.jetbrains:annotations:15.0'
compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
}
apply plugin: 'com.google.gms.google-services'
android.packagingOptions {
exclude 'LICENSE.txt'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/NOTICE.txt'
exclude 'META-INF/rxjava.properties'
}
configurations.all {
resolutionStrategy.eachDependency { DependencyResolveDetails details ->
def requested = details.requested
if (requested.group == 'com.android.support') {
if (!requested.name.startsWith("multidex")) {
details.useVersion "$supportVersion"
}
}
}
}
With no success I tried this
tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
sourceCompatibility = JavaVersion.VERSION_1_6
targetCompatibility = JavaVersion.VERSION_1_6
kotlinOptions {
jvmTarget = '1.6'
apiVersion = '1.1'
languageVersion = '1.1'
}
}
and this
tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
sourceCompatibility = JavaVersion.VERSION_1_8
targetCompatibility = JavaVersion.VERSION_1_8
kotlinOptions {
jvmTarget = '1.8'
apiVersion = '1.1'
languageVersion = '1.1'
}
}
Update
with the last version that uses 1.8 for kotlin I now get a different error:
Error:Execution failed for task ':app:compileDebugKotlin'.
Compilation error. See log for more details
I'm investigating now
This is my top level build.gradle
buildscript {
ext.kotlin_version = '1.1.2-4'
repositories {
jcenter()
}
dependencies {
classpath('com.android.tools.build:gradle:2.3.0') {
force = true
}
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle file
classpath 'com.google.gms:google-services:3.0.0'
classpath "io.realm:realm-gradle-plugin:2.1.1"
classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
allprojects {
repositories {
jcenter()
maven { url 'https://maven.fabric.io/public' }
maven { url "https://jitpack.io" }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

Answer 1

Retrolambda is not processing the Kotlin bytecode, and you should set the Kotlin compiler to specifically target 1.6 bytecode. This will not break anything in current version of Kotlin as it can generate the older bytecode for the same functionality.
compileKotlin {
kotlinOptions.jvmTarget = "1.6"
}
This is documented in the Kotlin Gradle Plugin attributes
For tests, also add:
compileTestKotlin {
kotlinOptions.jvmTarget = "1.6"
}