Speed up gradle build in multidex application

Question

My application has a bunch of librarys that are essential that is why I was forced to use multidex support library and it works nicely. But where the problem shows is in the gradle buid speed. It takes on average 2minutes to build and when I am developing and testing this is quite annoying.

Is there a way to speed up my debug builds?

Answer 1

You can speed-up your development builds by specifying the minimum SDK version = 21.
Official documentation includes a whole section about that.

Example (from documentation):

android {
    productFlavors {
        // Define separate dev and prod product flavors.
        dev {
            // dev utilizes minSDKVersion = 21 to allow the Android gradle plugin
            // to pre-dex each module and produce an APK that can be tested on
            // Android Lollipop without time consuming dex merging processes.
            minSdkVersion 21
        }
        prod {
            // The actual minSdkVersion for the application.
            minSdkVersion 14
        }
    }
          ...
    buildTypes {
        release {
            runProguard true
            proguardFiles getDefaultProguardFile('proguard-android.txt'),
                                                 'proguard-rules.pro'
        }
    }
}
dependencies {
  compile 'com.android.support:multidex:1.0.0'
}

Once you added the product flavors, you can use the devDebug task (instead of default debug task) for your development builds:
- from command line: run ./gradlew installDevDebug
- from Android Studio: open Build Variants window and select the devDebug build variant.

You should, of course, work against a device whose SDK >= 21.

---

There's also a solution for those who don't want to use flavors. As suggested in this gist, dynamically calculate the minSdkVersion value:

int minSdk = hasProperty('devMinSdk') ? devMinSdk.toInteger() : 14
apply plugin: 'com.android.application'

android {
    ...
    defaultConfig {
        minSdkVersion minSdk
        ...
    }
}

In this example, we're checking if devMinSdk property defined, and if true - we're using it. Otherwise, we default to 14.

How do we pass devMinSdk value to build script? Two options:

Using command line:

./gradlew installDebug -PdevMinSdk=21

Using Android Studio preferences:

Go to Preferences (Settings on Windows) -> Build, Execution, Deployment -> Compiler -> put -PdevMinSdk=21 in Command-line Options text box.