Issue 6213 - Configure building directory

README.md

 Adblock Plus Library for Android
 ================================
 
 An Android library project, tests and demo application for AdblockWebView widget.
 
 ## Updating the dependencies
 
 Adblock Plus for Android has dependencies that aren't in this repository.
 To update those, call:
 
@@ skipping 73 matching lines @@
 This will generate *.aar library artifact in the 'libadblockplus-android/build/outputs/aar/' directory.
 
 **Android permissions note**
 
 An app that uses the library have to add the following permissions to `AndroidManifest.xml`:
  * `<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>`
  * `<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>`
 
 (added automatically if building with Gradle or should be added manually otherwise).
 
+### Build directory configuration
+
+By default Gradle uses `build` directory to build modules, however it can be undesired
+for some use cases like CI or building as Chromium submodule.
+Set `GRADLE_BUILD_DIR` environment variable to configure build directory:
+
+    GRADLE_BUILD_DIR=/tmp ./gradlew clean assemble
+    
+Note
+
+    [Configuration] Building project in /tmp
+
+output while building
+
 ### Building with prebuilt shared V8
 
 This can be desired to use product's V8 (let's say Chromium) instead of built-in V8.
 Put prebuilt shared V8 library file(s) in ARCH directories and set `SHARED_V8_LIB_FILENAMES`
 environment variable before building. You can pass multiple filenames, separated with space.
 Libadblockplus is required to be linked with that library file(s).
 
 For example (build with Gradle):
 
     SHARED_V8_LIB_FILENAMES=libv8.cr.so ./gradlew clean assemble
@@ skipping 220 matching lines @@
 
 This will generate *.apk in the 'libadblockplus-android-webviewapp/bin/' directory.
 
 #### Building with Gradle
 
 In the project root directory run:
 
     ./gradlew assemble
 
 This will generate *.apk in the 'libadblockplus-android-webviewapp/build/outputs/apk/' directory.