Upgrade Gradle wrapper version to 8.6 and Android Gradle plugin version to 8.4.1 make my android studio unable to build release .apk file

Question

after recent update, my android studio make an error:

java.lang.NullPointerException: Cannot invoke "com.android.tools.r8.internal.Gk0.B()" because the return value of "com.android.tools.r8.internal.Jw.b()" is null

and this error avoids build release .apk file.

here is my build.gradle(app):

android {
    namespace '...'
    compileSdk 34

    defaultConfig {
        applicationId '...'
        minSdk 23
        targetSdk 34
        versionCode 11
        versionName '2.1.1'
        vectorDrawables.useSupportLibrary = true
        multiDexEnabled true
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled true
            shrinkResources true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }

    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_18
        targetCompatibility JavaVersion.VERSION_18
    }
    buildFeatures {
        buildConfig true
    }
}

dependencies {
    //some dependencies
}

here's my build.gradle(Project)

plugins {
    id 'com.android.application' version '8.4.1' apply false
    id 'com.android.library' version '8.4.1' apply false
}

I should add I have android.enableR8=true which is depreciated in my gradle.properties file, however change it to true, false or even removing it doesn't change anything.

any idea how to resolve this problem?

Nixon

Any success with this? I am facing the same issue as well – Variate

so it's not just me? is it some kind of bug? – Nixon

The issue seems to be in ucrop library itself: github.com/Yalantis/uCrop/issues/914 – Jollanta

Answer 1

After a long research and testing for a day, I found a solution. Adding this to proguard-rules.pro fixed the problem for now:

-keepclassmembers enum * { *; }

Is it safe to use such a command? If you guys have a better idea, I would appreciated it.

Nixon

I'm curious why do you know enum is the root cause of R8 failure? :think – Swamper

Just added this line and problem got fixed. Not sure how but i searched Stack a lot and used a lot of commands and code snips and this one worked. – Nixon

Answer 2

That is an issue with uCrop library. Instead of @Ashile solution which keeps all enum classes, you can use this more specific rule

-keep class com.yalantis.ucrop.util.RectUtils { *; }

You can find more info here: https://github.com/Yalantis/uCrop/issues/914

Jollanta

I didn't use this library and I had this error. But i can confirm some bug exist in new version. after the update i had the error and not before that. – Nixon

In the screenshot you demonstrated in the question, there was jetified-ucrop-2.2.6-runtime.jar so it seems you are using it or a library you are using is using it under the hood. Correct me if I am wrong. – Jollanta

I used this library github.com/Dhaval2404/ImagePicker and when I opened yours, they are very similar in action. maybe they inherit from each other? – Nixon

Yes, this library uses uCrop under the hood. See implementation 'com.github.yalantis:ucrop:2.2.6' at line 52 on github.com/Dhaval2404/ImagePicker/blob/master/… – Jollanta