title: Gradle does not generate an output APK
body: <p>I'm trying to generate an APK for my android project on the command line.
  I am running </p>
  
  <pre><code>./gradlew clean assembleProductionDebug
  </code></pre>
  
  <p>The output I get is:</p>
  
  <pre><code>:app:processProductionDebugManifest
  :app:processProductionDebugResources
  :app:generateProductionDebugSources
  :app:compileProductionDebugJava
  Note: Some input files use or override a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  :app:preDexProductionDebug
  :app:dexProductionDebug
  :app:processProductionDebugJavaRes UP-TO-DATE
  :app:validateDebugSigning
  :app:packageProductionDebug
  :app:zipalignProductionDebug
  :app:assembleProductionDebug
  
  BUILD SUCCESSFUL
  
  Total time: 2 mins 29.574 secs
  </code></pre>
  
  <p>However, my build/outputs folder is empty. The same happens when I run 
  ./gradlew assemble</p>
  
  <p>The only relevant thing I could search for is potentially <a href="https://gradle.org/docs/current/dsl/org.gradle.language.assembler.tasks.Assemble.html" rel="noreferrer">https://gradle.org/docs/current/dsl/org.gradle.language.assembler.tasks.Assemble.html</a> but how do I specify the objectFileDir in the build.gradle?</p>
  
  <p>Note: running</p>
  
  <pre><code>./gradlew clean installProductionDebug
  </code></pre>
  
  <p>does successfully install the APK on my device. </p>
  
  <p>Relevant build.gradle:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'git-dependencies'
  apply plugin: 'testfairy'
  apply plugin: 'org.robolectric'
  
  
  android {
      compileSdkVersion 21
      buildToolsVersion "21.1.2"
  
      defaultConfig {
          applicationId "com.test.androidas"
          minSdkVersion 15
          targetSdkVersion 21
          versionCode 1
          versionName "1.0"
      }
  
      signingConfigs {
          release {
               storeFile file("as.keystore")
               storePassword "***"
               keyAlias "as"
               keyPassword "***"
          }
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
              signingConfig signingConfigs.release
          }
      }
  
  
      productFlavors {
          production {
              applicationId "com.antsquare.test"
              versionCode 1
          }
  
          staging {
              applicationId "com.antsquare.test.staging"
              versionCode 1
          }
      }
  
      packagingOptions {
          exclude 'META-INF/DEPENDENCIES.txt'
          exclude 'META-INF/LICENSE.txt'
          exclude 'META-INF/NOTICE.txt'
          exclude 'META-INF/NOTICE'
          exclude 'META-INF/LICENSE'
          exclude 'META-INF/DEPENDENCIES'
          exclude 'META-INF/notice.txt'
          exclude 'META-INF/license.txt'
          exclude 'META-INF/dependencies.txt'
          exclude 'META-INF/LGPL2.1'
      }
  
      testfairyConfig {
          apiKey '***'
          video "wifi"
          notify true
          testersGroups "ME"
          autoUpdate true
          videoQuality "low"
          videoRate "0.5"
      }
  }
  </code></pre>