Why proGuard doesn't work when its active?-CodePudding

I want to reduce my app size. I saw some tutorials and understood that I have to use the following code in build.gradle(app) :

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

I tried it but the app size didn't change until I added another code and it worked :

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

My question is why it should be use debug because it wasn't used in tutorials I saw.

I'm worried about slow app with this way.

Note : My Android Studio version is 3.5 and my gradle version is 7.0.4.

CodePudding user response：

An Android Studio project default buildtype is debug, you can see it on "Build Variants" panel on left bottom corner of Android Studio. You can also change it to release