Unable To Build Feature Modules In A Multi-flavor App

I am using Gradle 4.4 with Gradle-Android plugin 3.1.1 on Android Studio 3.1.1. I have 2 flavors 'a' and 'b' and I am unable to build my project due to the following error: Cannot

Solution 1:

Thanks to user TWL who pointed me towards google samples for instant apps, with an example for flavors.

We need flavor declarations in all the feature modules, application module and instant-app module as well. Library modules can be skipped as of today with plugin version 3.1.1. In other words, have this section in all feature and installed/instant modules:

flavorDimensions "dim"
productFlavors{
    a{
        dimension "dim"
    }
    b{
        dimension "dim"
    }
}

Solution 2:

FWIW you don't have to have matching flavors in your modules. You can tell it to fallback to the default build types.

By using matchingFallbacks

buildTypes {
    aDebug {
        testCoverageEnabled truematchingFallbacks= ['debug']
    }
    bDebug {
        testCoverageEnabled truematchingFallbacks= ['debug']
    }
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'// This one already looks for 'release' which is added by default, so no need for fallback
    }
}

https://developer.android.com/studio/build/dependencies#resolve_matching_errors

Solution 3:

It seems you didn't specify difference in the names of a and b packages. Below is my working implementation of flavor feature for API 25 and com.android.tools.build:gradle:2.3.1 in the app level build.gradle of AS 2.3.3:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.3"

    defaultConfig {
        applicationId "com.example"
        minSdkVersion 14
        targetSdkVersion 25
        versionCode 1
        versionName "1.00"
    }

    signingConfigs {
        config {
            storeFile file(STORE_PATH)
            keyAlias KEY_ALIAS
            keyPassword KEY_PASSWORD
            storePassword KEYSTORE_PASSWORD
        }
    }

    productFlavors {
        nosync {
            applicationIdSuffix ".nosync"
            versionNameSuffix '-nosync'
            signingConfig signingConfigs.config
        }
        sync {
            signingConfig signingConfigs.config
        }
    }

    buildTypes {
        release {
            debuggable false
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            signingConfig signingConfigs.config
        }
        debug {
            debuggable true
            signingConfig signingConfigs.config
        }
    }

dependencies {
    ...
}

Take a look on difference

applicationIdSuffix ".nosync"
versionNameSuffix '-nosync'

between nosync and sync flavors. It will change the package name of nosyncapk.