Why is the Android Studio Proguard mapping.txt file empty (0 KB)?

Question

In the last week, the Proguard mapping.txt file is suddenly being created as an empty file (0 KB) for all of my Android Studio projects. The file used to be generated properly each time I created a build. The following files are generated each time I create a build:

seeds.txt
resources.txt
usage.txt
mapping.txt

All of the files, except the mapping.txt, are being generated properly each time the build is created. The mapping file is also generated, but has no text in it.

defaultConfig {
        applicationId "com.xxxxxxxx.xxxxxxxxxxxxx"
        minSdkVersion 19
        targetSdkVersion 26
        versionCode xxx
        versionName "x.xx.x.xxx"
        multiDexEnabled true
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        debug {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            signingConfig signingConfigs.config
            debuggable false
        }
    }

Is there a setting in Android Studio that may have been inadvertently switched and is preventing the mapping.txt file from being generated properly? I've been working on this for 3 days and have even created several new projects that also create an empty mapping file.

Any help you can give me is greatly appreciated. Please let me know if you need additional info. Thank you in advance.

This is my ProGuard-rules.pro file:

-ignorewarnings
-keep class * {
    public private *;
}

-keep class android.support.v7.widget.ShareActionProvider { *; }

-dontwarn retrofit2.Platform$Java8
-dontwarn retrofit.Platform$Java8

-dontwarn okio.**
-keep class com.google.android.gms.** { *; }
-keepclassmembers class * implements android.os.Parcelable {
   static ** CREATOR;
}
-keepclassmembers class * implements com.google.android.gms.common.internal.ReflectedParcelable {
   static ** CREATOR;
}

-keep class com.fasterxml.jackson.databind.ObjectMapper {
    public <methods>;
    protected <methods>;
}
-keep class com.fasterxml.jackson.databind.ObjectWriter {
    public ** writeValueAsString(**);
}
-keepnames class com.fasterxml.jackson.** { *; }
-dontwarn com.fasterxml.jackson.databind.**
-dontwarn com.fasterxml.jackson.core.**
-dontwarn com.fasterxml.jackson.annotation.**

#MobFox Integration
-keep class com.mobfox.** { *; }
-keep class com.mobfox.adapter.** {*;}
-keep class com.mobfox.sdk.** {*;}

#Ad Colony Integration
-keepclassmembers class com.adcolony.sdk.ADCNative** {
    *;
}

# MoPub Integration
# Keep public classes and methods.
-keepclassmembers class com.mopub.** { public *; }
-keep public class com.mopub.**
-keep public class android.webkit.JavascriptInterface {}

# Explicitly keep any custom event classes in any package.
-keep class * extends com.mopub.mobileads.CustomEventBanner {}
-keep class * extends com.mopub.mobileads.CustomEventInterstitial {}
-keep class * extends com.mopub.nativeads.CustomEventNative {}
-keep class * extends com.mopub.nativeads.CustomEventRewardedAd {}

# Keep methods that are accessed via reflection
-keepclassmembers class ** { @com.mopub.common.util.ReflectionTarget *; }
-keepclassmembers class com.mopub.mobileads.CustomEventBannerAdapter {!private !public !protected *;}

# Viewability support
-keepclassmembers class com.integralads.avid.library.mopub.** { public *; }
-keep public class com.integralads.avid.library.mopub.**
-keepclassmembers class com.moat.analytics.mobile.mpub.** { public *; }
-keep public class com.moat.analytics.mobile.mpub.**

# Support for Android Advertiser ID.
-keep class com.google.android.gms.common.GooglePlayServicesUtil {*;}
-keep class com.google.android.gms.ads.identifier.AdvertisingIdClient {*;}
-keep class com.google.android.gms.ads.identifier.AdvertisingIdClient$Info {*;}

# Support for Google Play Services
# http://developer.android.com/google/play-services/setup.html
-keep class * extends java.util.ListResourceBundle {
    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @com.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}

# Support for GlideApp
-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public class * extends com.bumptech.glide.AppGlideModule
-keep public enum com.bumptech.glide.load.resource.bitmap.ImageHeaderParser$** {
  **[] $VALUES;
  public *;
}
-dontwarn com.bumptech.glide.load.engine.bitmap_recycle.LruBitmapPool
-dontwarn com.bumptech.glide.load.resource.bitmap.Downsampler
-dontwarn com.bumptech.glide.load.resource.bitmap.HardwareConfigState

# Suppot for AerServ

# AerServ SDK
-keep class com.aerserv.** { *; }
-keepclassmembers class com.aerserv.** { *; }

# Moat
-keep class com.moat.** {*;}
-dontwarn com.moat.**

# For Adcolony
-dontwarn android.webkit.**
-dontwarn com.adcolony.**
-keep class com.adcolony.sdk.* { *; }

# For Admob
-keep class com.google.android.gms.ads.** { *; }

# For Applovin
-dontwarn com.applovin.**
-keep class com.applovin.** { *; }

# For AppNext
-keep class com.appnext.** { *; }
-dontwarn com.appnext.**

# For Chartboost
-dontwarn com.chartboost.sdk.**
-keep class com.chartboost.sdk.** { *; }

# For Facebook
-dontwarn com.facebook.ads.**
-keep class com.facebook.ads.** { *; }

# For Millennial Media
-dontwarn com.millennialmedia.**
-keep class com.millennialmedia.** { *; }

# For Mopub
-dontwarn com.mopub.**
-keep class com.mopub.** { *; }

# For myTarget
-dontwarn com.my.target.ads.**
-keep class com.my.target.ads.** { *; }

# For RhythmOne
-dontwarn com.rhythmone.ad.sdk.**
-keep class com.rhythmone.ad.sdk.** { *; }

# For Tremor
-dontwarn com.tremorvideo.sdk.**
-keep class com.tremorvideo.sdk.android.videoad.** { *; }

# For Unity Ads
-dontwarn com.unity3d.ads.**
-keep class com.unity3d.ads.** { *; }

# For Vungle
-dontwarn com.vungle.publisher.**
-keep class com.vungle.publisher.** { *; }

# For Flurry by Yahoo
-dontwarn android.support.customtabs.**
-dontwarn com.flurry.android.**
-dontwarn com.inmobi.**
-keep class com.flurry.** { *; }

# For InMobi by Yahoo
-keepattributes SourceFile,LineNumberTable
-keep class com.inmobi.** { *; }
-keep public class com.google.android.gms.**
-dontwarn com.google.android.gms.**
-dontwarn com.squareup.picasso.**
-keep class com.google.android.gms.ads.identifier.AdvertisingIdClient{
     public *;
}
-keep class com.google.android.gms.ads.identifier.AdvertisingIdClient$Info{
     public *;
}
# skip the Picasso library classes
-keep class com.squareup.picasso.** {*;}
-dontwarn com.squareup.picasso.**
-dontwarn com.squareup.okhttp.**

# Google Android Classes
-keep public class com.google.android.gms.* { public *; }
-dontwarn com.google.android.gms.**

-keep class * extends java.util.ListResourceBundle {
    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @com.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}

# Mapbox
-dontwarn com.mapbox.mapboxsdk.plugins.locationlayer.**
-dontwarn okhttp3.internal.platform.ConscryptPlatform.**

Answer 1

This was due to a 3rd party library that was blocking the mapping file from being generated properly. I've contacted the library creator and it's been fixed.