Gradle productFlavors raises error - Cannot add task ':assembleTest' as a task with that name already exists

Question

New to Gradle, trying to create build variants. I just added a productFlavor to the gradle file all of a sudden I get this strange error

$ gradle tasks
Creating properties on demand (a.k.a. dynamic properties) has been deprecated and is scheduled to be removed in Gradle 2.0. Please read http://gradle.org/docs/current/dsl/org.gradle.api.plugins.ExtraPropertiesExtension.html for information on the replacement for dynamic properties.
Deprecated dynamic property: "srcDirs" on "source set aild", value: "[src]".

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'SegmentIO'.
> Cannot add task ':assembleTest' as a task with that name already exists.

Here is my complete build.gradle

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:0.8.+'
    }
}

apply plugin: 'android'


dependencies {
    compile files('libs/android-support-v4.jar')
}

android {
    buildToolsVersion "19.0.1"
    compileSdkVersion 17

    productFlavors {
        test {
        }

        prod {
        }
    }

     sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src', 'bundled-src']
            resources.srcDirs = ['src']
            aild.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
        }

        // test.assets.srcDirs = ['$java-project-root/assets/test']
        // prod.assets.srcDirs = ['$java-project-root/assets/test']

        instrumentTest.setRoot('tests')
    }

    dependencies {
        compile fileTree(dir: './libs', include: 'Amplitude.jar')
    }
}

Answer 1

I see two problems:

Deprecated dynamic property: "srcDirs" on "source set aild", value: "[src]".

is because you misspelled aild.srcDirs in your build file -- it should be aidl.srcDirs.

> Cannot add task ':assembleTest' as a task with that name already exists.

is because you're trying to create a flavor named "test", but this is being used by something else in the build and it's colliding. Try using a different name.

To be more specific, the Android plugin makes a number of tasks based off the flavor name (it does this with build types, too). If you have a flavor name "foo", assembleFoo performs an assemble but only on the foo flavor. There's already an assembleTest task, so it's colliding when it tries to make one for your flavor.