Unable to generate signed apk with proguard

Question

I'm getting the following error when I'm trying to generate a signed apk with proguard enabled.

Error:Uncaught translation error: com.android.dx.cf.code.SimException: com.android.dx.rop.cst.CstMethodRef cannot be cast to com.android.dx.rop.cst.CstInterfaceMethodRef
Possible causes for this unexpected error include:<ul><li>Gradle's dependency cache may be corrupt (this sometimes occurs after a network connection timeout.)
<a href="syncProject">Re-download dependencies and sync project (requires network)</a></li><li>The state of a Gradle build process (daemon) may be corrupt. Stopping all Gradle daemons may solve this problem.
<a href="stopGradleDaemons">Stop Gradle build processes (requires restart)</a></li><li>Your project may be using a third-party plugin which is not compatible with the other plugins in the project or the version of Gradle requested by the project.</li></ul>In the case of corrupt Gradle processes, you can also try closing the IDE and then killing all Java processes.

This is what I'm using/doing:

1. Android studio 2.2
2. play-services version 9.6.1

3. proguard-rules.pro

   • dontwarn okio.
   • dontwarn retrofit2.Platform$Java8
   • keep public class com.google.android.gms.
   • dontwarn com.google.android.gms.
   • keepattributes InnerClasses,EnclosingMethod

4. gradle(app)

   defaultConfig {
       applicationId "com.something.something"
       minSdkVersion 15
       targetSdkVersion 23
       versionCode 3
       versionName "3.0"
   
       // Enabling multidex support.
       multiDexEnabled true
   
       testInstrumentationRunner "com.android.test.runner.MultiDexTestRunner"
   }
   buildTypes {
       release {
           minifyEnabled true
           proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
       }
   }
   productFlavors {
   }
   

5. Libraries that I'm using:

   • com.radiusnetworks:proximitykit-android:0.+@aar
   • com.squareup.retrofit2:retrofit:2.0.2
   • com.google.firebase:firebase-messaging:9.6.1

Answer 1

Based from this SO answer, the code below should work as long as you don't need any special ProGuard configuration.

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

If you do, use your original proguardFiles entry and create the file /Users/franek/Documents/Android_Studio_Melange/app/proguard-rules.txt then put your custom rules in this file.

This thread might also help. Add the following lines to the proguard-rules.pro file to resolve the issue of being unable to generate a signed APK using Proguard (Minify Enabled = true).

keep class org.apache.http.**
keep class android.net.http.**
dontwarn com.google.android.gms.**