title: Execution failed for task ':app:transformClassesWithAndroidGradleClassShrinkerForDebug' in Android Studio 3.1
body: <p>I've just upgraded from Android Studio <code>3.1</code> to Android Studio <code>3.1.1</code> (but still using Gradle build tool <code>3.0.0</code>). When I run my app it causes this error:</p>
  
  <pre><code>:app:transformClassesWithAndroidGradleClassShrinkerForDebug
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Interceptor
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Interceptor
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Request
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: okio/Okio
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/ResponseBody
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okio/Okio
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Request
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Response
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Headers
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/ResponseBody
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Interceptor$Chain
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Response$Builder
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/Response
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Headers
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/RequestBody
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/OkHttpClient$Builder
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/HttpUrl
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: com/squareup/okhttp/OkHttpClient
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: okio/BufferedSource
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Interceptor$Chain
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/Response$Builder
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okhttp3/RequestBody
  com/android/tools/profiler/agent/okhttp/OkHttp2Interceptor references unknown class: okio/BufferedSink
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okio/BufferedSource
  com/android/tools/profiler/agent/okhttp/OkHttp3Interceptor references unknown class: okio/BufferedSink
  :app:transformClassesWithAndroidGradleClassShrinkerForDebug FAILED
  :app:buildInfoGeneratorDebug
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':app:transformClassesWithAndroidGradleClassShrinkerForDebug'.
  &gt; Warnings found during shrinking, please use -dontwarn or -ignorewarnings to suppress them.
  </code></pre>
  
  <p>But I'm NOT using <code>okhttp</code> or any Http library (like Retrofit,..) in my project.</p>
  
  <p>This error also happens when I'm upgrading Gradle build tool to the newest version <code>3.1.1</code>. I don't know why, everything is fine when I downgrade back to Android Studio <code>3.1.0</code>.</p>
  
  <p><strong>app/build.gradle</strong></p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      defaultConfig {
          applicationId "com.z.a.zcamera"
          minSdkVersion 14
          targetSdkVersion 26
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
          debug {
              minifyEnabled true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      implementation fileTree(include: ['*.jar'], dir: 'libs')
      implementation project(path: ':libzcamera')
      implementation 'com.android.support:support-v4:26.1.0'
  }
  </code></pre>
  
  <p><strong>Update:</strong></p>
  
  <p>I think it is caused by Android Profiler tool's new feature: <strong>the network profiler</strong> because of the <code>com/android/tools/profiler/agent</code> path and I'm turning ON the advanced profiling to track network payload.</p>
  
  <p>I also don't want to disable Proguard too.</p>
  
  <p>Any ideas? Please help me.</p>