Dexguard with Multidex

Question

I have a problem while integrating Dexguard in the projects that needs to enable Multidex, I get no compile errors but when launching the app it crashes with this error

java.lang.RuntimeException: Unable to instantiate application xx.xxx.xxx.XXXApp: java.lang.ClassNotFoundException: Didn't find class "xx.xxx.xxx.XXXApp" on path: DexPathList

This is the app.gradle file:

apply plugin: 'com.android.application'
...
apply plugin: 'dexguard'

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"
    defaultConfig {
        applicationId "xx.xxx.xxx"
        ...
        multiDexEnabled true
    }
    buildTypes {
        debug {
            proguardFile getDefaultDexGuardFile('dexguard-debug.pro')
            proguardFile 'dexguard-project.txt'
            //proguardFile 'proguard-project.txt'
        }
        release {
            proguardFile getDefaultDexGuardFile('dexguard-release.pro')
            proguardFile 'dexguard-project.txt'
            //proguardFile 'proguard-project.txt'
        }
    }
    flavorDimensions "server"
    productFlavors {
        dev {
            applicationIdSuffix ".dev"
            dimension "server"
        }
        ...
        prod {
            dimension "server"
        }
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    ...

    implementation 'com.android.support:multidex:1.0.1'

    //support libraries
    ...
    //play services
    ...
    //architecture components
    ...
    //others
    ...
}

apply plugin: 'com.google.gms.google-services'

In the dexguard-project.txt file I simply added the -multidex option

I also tried using -keep public class * extends android.app.Application but without luck.

EDIT

I use a custom application class that extends another custom one -.- so I added the snippet below

@Override
protected void attachBaseContext(Context base) {
    super.attachBaseContext(base);
    MultiDex.install(this);
}

And this is the relative part of the manifest

<application
        android:name=".XXXApp"
        ...

Anybody has faced the same issue?

Answer 1

In the end the solution was quite simple, just changed multidexEnabled to false

defaultConfig {
        applicationId "xx.xxx.xxx"
        ...
        multiDexEnabled false
    }