non riusciva a trovare com.google.firebase: Firebase-core: 9.0.0

Question

Dopo aver seguito le istruzioni un po 'incoerenti here e here ottengo un errore durante l'esecuzione di una sincronizzazione Gradle dicendo could not find com.google.firebase:firebase-core:9.0.0

Tutte le idee per spiegare perché questo sta accadendo ?

app/build.gradle

apply plugin: 'com.android.application' 

android { 
    compileSdkVersion 23 
    buildToolsVersion "23.0.3" 
    defaultConfig { 
     minSdkVersion 15 
     targetSdkVersion 23 
     versionCode 1 
     versionName "1.0" 
    } 
    buildTypes { 
     release { 
      minifyEnabled false 
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
     } 
    } 
    productFlavors { 
     free { 
      applicationId ... 
     } 

     paid { 
      applicationId ... 
     } 
    } 
} 

dependencies { 
    compile fileTree(include: ['*.jar'], dir: 'libs') 
    testCompile 'junit:junit:4.12' 
    compile 'com.android.support:appcompat-v7:23.3.0' 
    compile 'com.android.support:support-v4:23.3.0' 

    freeCompile 'com.google.firebase:firebase-core:9.0.0' 
    freeCompile 'com.google.firebase:firebase-ads:9.0.0:9.0.0' 
} 

apply plugin: 'com.google.gms.google-services' 

root/build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules. 

buildscript { 
    repositories { 
     jcenter() 
    } 
    dependencies { 
     classpath 'com.android.tools.build:gradle:2.1.0' 
     classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8' 
     classpath 'com.google.gms:google-services:3.0.0' 

     // NOTE: Do not place your application dependencies here; they belong 
     // in the individual module build.gradle files 
    } 
} 

allprojects { 
    repositories { 
     jcenter() 
    } 
} 

task clean(type: Delete) { 
    delete rootProject.buildDir 
} 

Answer 1

In primo luogo, è necessario aggiornare Play Services Library a rev.30:

e allora hai un piccolo problema in questa riga:

freeCompile 'com.google.firebase:firebase-ads:9.0.0:9.0.0' 

probabilmente necessario correggere a questo:

freeCompile 'com.google.firebase:firebase-ads:9.0.0'