Build.gradle not syncing Android Studio

Question

I've the following dependencies in my Android app's build.gradle file.

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile files('libs/mxparser.jar')

    // View dependency injection library by Jake Wharton
    compile 'com.jakewharton:butterknife:8.5.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1'

    // apt command comes from the android-apt plugin
    compile 'com.google.dagger:dagger:2.9'
    annotationProcessor "com.google.dagger:dagger-compiler:2.9"
    provided 'javax.annotation:jsr250-api:1.0'

    // Crash reporting SDK
    compile('com.crashlytics.sdk.android:crashlytics:2.6.7@aar') {
        transitive = true;
    }
}

However when I add Crashlytics as dependency, I get the following error:

Error:Failed to resolve: annotationProcessor
Failed to resolve: com.crashlytics.sdk.android:crashlytics:2.6.7

Project Build.gradle:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0'
        classpath 'com.jakewharton:butterknife-gradle-plugin:8.5.1'

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

Answer 1

Make sure you have added

apply plugin: 'io.fabric'

repositories {
  maven { url 'https://maven.fabric.io/public' }
}

to your app's build.gradle file otherwise Crashlytics won't resolve and give weird errors.