The Android Gradle Plugin

This page describes how to build the Android Gradle plugin, and to test it.

Get the Source Code

Follow the instructions here to checkout the source code.

Once you have checked out the source code, the Gradle Plugin code can be found under tools/base

Building and editing the Android Gradle plugin

To edit the plugin import the Gradle project rooted in the tools directory in to the most recent Intellij IDEA EAP.

You can run unit and integration tests directly from within Intellij IDEA. You can also run them with Gradle from the command line

To build AGP for use in other projects, use the “Execute Gradle Task” action to run :publishAndroidGradleLocal (or :publishLocal if you also need the databinding libraries)

The above command publishes the plugin to a local Maven repository located in ../out/repo/, and it is also done as part of running the integration tests.

Debugging the Android Gradle plugin

To debug unit tests simply use the debug action in Intellij IDEA.

To debug the Android Gradle Plugin being run from integration tests:

1. Add the environment variable DEBUG_INNER_TEST=1 to the run configuration
2. Run the test in IDEA (Run, not debug, unless you want to debug both the test and the plugin at the same time)
3. Connect the Intellij remote debugger to port 5006

Using locally built plugin in a project

To test your own Gradle projects, using your modified Android Gradle plugin, modify the build.gradle file to point to your local repository (where the above publishLocal target installed your build).

For example, if you ran the repo init command above in /my/aosp/work, then the repository will be in /my/aosp/work/out/repo.

You may need to change the version of the plugin as the version number used in the development branch is typically different from what was released. You can find the version number of the current build in tools/buildSrc/base/version.properties.

For example:

buildscript {
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:4.2.0'
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

buildscript {
    repositories {
        maven { url '/my/aosp/work/out/repo' }
        google()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:7.0.0-dev'
    }
}

allprojects {
    repositories {
        maven { url '/my/aosp/work/out/repo' }
        google()
        mavenCentral()
    }
}

To debug a project like this simply run

$ ./gradlew --no-daemon -Dorg.gradle.debug=true someTask

and connect a remote debugger to port 5005.

Preparing your changes for submission

If you‘ve made changes, make sure you run the tests to ensure you haven’t broken anything:

cd base/build-system && ../../gradlew test

Presubmit runs all the tests, so another strategy is to guess which tests may be affected by your change and run them locally but rely on the presubmit tests to run all the integration tests.