I am running into this issue almost everytime when I add a new module to my app but this time I am not able to resolve it at all. I am sick and tired of not friendly messages and tools of gradle. Someone please help: If you need dependencies output too let me know - it's big :(
Error: :app:transformClassesWithJarMergingForDebug FAILED FAILURE: Build failed with an exception. * What went wrong: Execution failed for task ':app:transformClassesWithJarMergingForDebug'. com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: com/google/appengine/tools/appstats/Inter nalProtos$1.class
Here are 4 gradle files:
Top level gradle:
buildscript { repositories { jcenter() mavenCentral() } dependencies { classpath 'com.android.tools.build:gradle:1.5.0' classpath 'com.jakewharton.hugo:hugo-plugin:1.2.1' classpath 'com.google.gms:google-services:1.5.0-beta2' // NOTE: Do not place your application dependencies here; they belong // in the individual module build.gradle files } } allprojects { repositories { jcenter() mavenCentral() } } App gradle:
apply plugin: 'com.android.application' apply plugin: 'hugo' android { compileSdkVersion 23 buildToolsVersion "23.0.1" defaultConfig { applicationId "com.app.myapp" minSdkVersion 15 targetSdkVersion 23 versionCode 1 multiDexEnabled true versionName "1.0" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } compileOptions { sourceCompatibility JavaVersion.VERSION_1_7 targetCompatibility JavaVersion.VERSION_1_7 } } apply plugin: 'com.google.gms.google-services' dependencies { compile fileTree(include: ['*.jar'], dir: 'libs') compile files('libs/nineoldandroids-2.4.0.jar') compile 'com.android.support:appcompat-v7:23.1.1' compile 'com.google.android.gms:play-services:8.3.0' compile 'com.android.support:cardview-v7:23.1.1' compile 'com.android.support:design:23.1.1' compile 'com.android.support:gridlayout-v7:23.1.1' compile 'com.android.support:mediarouter-v7:23.1.1' compile 'com.android.support:palette-v7:23.1.1' compile 'com.android.support:recyclerview-v7:23.1.1' compile 'com.android.support:support-v13:23.1.1' compile 'com.jakewharton:butterknife:7.0.1' compile 'com.mikhaellopez:circularimageview:2.1.1' compile 'com.cocosw:bottomsheet:0.+@aar' compile 'com.github.bumptech.glide:okhttp-integration:1.3.1' compile 'com.google.android.gms:play-services-auth:8.3.0' compile 'com.google.android.gms:play-services-gcm:8.3.0' compile project(path: ':backend', configuration: 'android-endpoints') compile project(path: ':commons') } Backend gradle:
buildscript { repositories { jcenter() } dependencies { classpath 'com.google.appengine:gradle-appengine-plugin:1.9.18' } } repositories { jcenter(); } apply plugin: 'java' apply plugin: 'war' apply plugin: 'appengine' sourceCompatibility = JavaVersion.VERSION_1_7 targetCompatibility = JavaVersion.VERSION_1_7 dependencies { appengineSdk 'com.google.appengine:appengine-java-sdk:1.9.18' compile 'com.google.appengine:appengine-endpoints:1.9.18' compile 'com.google.appengine:appengine-endpoints-deps:1.9.18' compile 'javax.servlet:servlet-api:2.5' compile 'com.ganyo:gcm-server:1.0.2' compile project(path: ':commons') } appengine { downloadSdk = true appcfg { oauth2 = true } endpoints { getClientLibsOnBuild = true getDiscoveryDocsOnBuild = true } } Commons gradle:
apply plugin: 'java' dependencies { compile 'com.googlecode.objectify:objectify:4.0b3' compile 'com.google.code.gson:gson:2.5' } 
