Another experiment

.travis.yml

@@ -40,4 +40,7 @@ before_script:
   - chmod +x ./wait_for_emulator.sh
   - ./wait_for_emulator.sh
   - adb devices
-  - adb shell input keyevent 82 &
+  - adb shell input keyevent 82 &
+
+script:
+  - ./gradlew clean check connectedCheck -x library:signArchives -PdisablePreDex

app/build.gradle

@@ -49,17 +49,7 @@ dexcount {
     verbose = false
 }
 
-ext {
-    travisBuild = System.getenv("TRAVIS") == "true"
-    // allows for -Dpre-dex=false to be set
-    preDexEnabled = "true".equals(System.getProperty("pre-dex", "true"))
-}
-
 android {
-    dexOptions {
-        // Skip pre-dexing when running on Travis CI or when disabled via -Dpre-dex=false.
-        preDexLibraries = preDexEnabled && !travisBuild
-    }
 
     testOptions {
         // Allows Android code to be called from unit tests without causing a crash.

build.gradle

@@ -24,3 +24,21 @@ allprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+/**
+ * Improve build server performance by allowing disabling of pre-dexing
+ * (see http://tools.android.com/tech-docs/new-build-system/tips#TOC-Improving-Build-Server-performance.)
+ */
+project.ext.preDexLibs = !project.hasProperty('disablePreDex')
+
+subprojects {
+    project.plugins.whenPluginAdded { plugin ->
+        if (rootProject.ext.has('preDexLibs')) {
+            if ("com.android.build.gradle.AppPlugin".equals(plugin.class.name)) {
+                project.android.dexOptions.preDexLibraries = rootProject.ext.preDexLibs
+            } else if ("com.android.build.gradle.LibraryPlugin".equals(plugin.class.name)) {
+                project.android.dexOptions.preDexLibraries = rootProject.ext.preDexLibs
+            }
+        }
+    }
+}