Develop Reference

Can't build apk in release version

When I deploy apk in debug version there is no warning, but when I try to build apk in release version I got this warning, please anybody help.
Warning:com.jjf2017.activity.MainActivity$43$$Lambda$1: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.ArtistIDFragment$$Lambda$1: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.ArtistIDFragment$$Lambda$2: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.ArtistINFragment$$Lambda$1: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.ArtistINFragment$$Lambda$2: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.CcFragment$$Lambda$1: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:com.jjf2017.fragment.TicketFragment$$Lambda$1: can't find referenced class java.lang.invoke.LambdaForm$Hidden
Warning:org.joda.time.DateMidnight: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.DateTime: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.DateTimeZone: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.DateTimeZone: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Days: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Days: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Duration: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Hours: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Hours: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Instant: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.LocalDate: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.LocalDate: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.LocalDateTime: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.LocalDateTime: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.LocalTime: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.LocalTime: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Minutes: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Minutes: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.MonthDay: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.MonthDay: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Months: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Months: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.MutableDateTime: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.MutablePeriod: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Period: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Seconds: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Seconds: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Weeks: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Weeks: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.YearMonth: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.YearMonth: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.Years: can't find referenced class org.joda.convert.FromString
Warning:org.joda.time.Years: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.base.AbstractDateTime: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.base.AbstractDuration: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.base.AbstractInstant: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.base.AbstractPeriod: can't find referenced class org.joda.convert.ToString
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles$Lookup
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandle
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandle
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles$Lookup
Warning:retrofit2.Platform$Java8: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:there were 52 unresolved references to classes or interfaces.
Warning:Exception while processing task java.io.IOException: Please correct the above warnings first.
Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.
Job failed, see logs for details

Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease' means that
you're using proguard in release.
Try to set minifyEnabled option in your build.gradle file to false.
Like this:
buildTypes {
release {
minifyEnabled false
...
}
}

if your app still working when you make
minifyEnabled false
then you have to dontwarn manually every warning that you have with -dontwarn
Exempel: -dontwarn java.lang.invoke.**

Proguard causes 100 "can't find referenced class" warnings, ignores keep rules for springframework and jackson

My code compiles and runs fine in debug mode, but once I use a build configuration with minifyEnabled true I get these warnings which prevent compilation:
Warning:there were 100 unresolved references to classes or interfaces.
Warning:there were 2 unresolved references to program class members.
For readabilities sake I'll include the full output at the bottom.
There are two libraries that are causing these warnings, springframework and jackson. Those libraries are included in my project via gradle like so:
compile 'com.fasterxml.jackson.core:jackson-annotations:2.8.5'
compile 'com.fasterxml.jackson.core:jackson-core:2.8.5'
compile 'com.fasterxml.jackson.core:jackson-databind:2.8.5'
apt "org.androidannotations:rest-spring:$AAVersion"
compile "org.androidannotations:rest-spring-api:$AAVersion"
compile 'org.springframework.android:spring-android-rest-template:2.0.0.M3'
If I use -dontwarn for both of these libraries, like many people suggest for these types of issues, the app compiles but crashes with an obfuscated crashlog during startup - I tried retracing it with the mapping file, but that's not working either - I'm reasonably certain that the app crashes due to the autogenerated (through android annotations) class RestClient_ when initializing a jackson mapping class, the exception is the following:
java.lang.NoSuchFieldError: No static field PUBLIC_ONLY of type
Lcom/myapp/app/mv$a; in class Lcom/myapp/app/mv$a; or its superclasses
(declaration of 'com.myapp.app.mv$a' appears in
/data/app/com.myapp.app-1/base.apk)
Although on a different phone, the exception has no message. It's pretty obvious that this is a result of proguard.
My full proguard file can be found here https://gist.github.com/Syzygy2048/02a44032611d40720bad36b5e3b37db6
Here are a couple of things I already tried (I tried more, but I only started writing things down after a while). The attempts focus on fixing springframework first. (Had to put this in a gist because stackoverflow wouldn't let me post otherwise)
https://gist.github.com/Syzygy2048/f1bdabc9f2ea091aa8faec67c62dd8bb
full error log:
Information:Gradle tasks [:myappApp:assembleMyappPublicRelease]
Warning:org.springframework.core.convert.support.ConvertingPropertyEditorAdapter: can't find superclass or interface java.beans.PropertyEditorSupport
Warning:com.fasterxml.jackson.databind.ext.DOMSerializer: can't find referenced class org.w3c.dom.bootstrap.DOMImplementationRegistry
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.Transient
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.ConstructorProperties
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.nio.file.Path
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.Transient
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.ConstructorProperties
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.Transient
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.ConstructorProperties
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.Transient
Warning:com.fasterxml.jackson.databind.ext.Java7SupportImpl: can't find referenced class java.beans.ConstructorProperties
Warning:com.fasterxml.jackson.databind.ext.NioPathDeserializer: can't find referenced class java.nio.file.Path
Warning:com.fasterxml.jackson.databind.ext.NioPathDeserializer: can't find referenced class java.nio.file.Paths
Warning:com.fasterxml.jackson.databind.ext.NioPathDeserializer: can't find referenced class java.nio.file.Path
Warning:com.fasterxml.jackson.databind.ext.NioPathSerializer: can't find referenced class java.nio.file.Path
Warning:org.springframework.core.convert.support.ConvertingPropertyEditorAdapter: can't find referenced class java.beans.PropertyEditorSupport
Warning:org.springframework.core.convert.support.ConvertingPropertyEditorAdapter: can't find referenced method 'void setValue(java.lang.Object)' in program class org.springframework.core.convert.support.ConvertingPropertyEditorAdapter
Warning:org.springframework.core.convert.support.ConvertingPropertyEditorAdapter: can't find referenced method 'java.lang.Object getValue()' in program class org.springframework.core.convert.support.ConvertingPropertyEditorAdapter
Warning:org.springframework.core.convert.support.ConvertingPropertyEditorAdapter: can't find referenced class java.beans.PropertyEditorSupport
Warning:org.springframework.http.client.HttpComponentsClientHttpRequest: can't find referenced class org.apache.http.entity.ByteArrayEntityHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequest: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsClientHttpRequest: can't find referenced class org.apache.http.client.methods.CloseableHttpResponse
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.HttpClients
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.protocol.HttpClientContext
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.Configurable
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig$Builder
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpGetHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpDeleteHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpHeadHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpOptionsHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpPostHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpPutHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpTraceHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.methods.HttpPatch
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.HttpClients
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.protocol.HttpClientContext
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig$Builder
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.client.config.RequestConfig
Warning:org.springframework.http.client.HttpComponentsClientHttpRequestFactory: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsClientHttpResponse: can't find referenced class org.apache.http.client.methods.CloseableHttpResponse
Warning:org.springframework.http.client.HttpComponentsClientHttpResponse: can't find referenced class org.apache.http.util.EntityUtilsHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpResponse: can't find referenced class org.apache.http.client.methods.CloseableHttpResponse
Warning:org.springframework.http.client.HttpComponentsClientHttpResponse: can't find referenced class org.apache.http.util.EntityUtilsHC4
Warning:org.springframework.http.client.HttpComponentsClientHttpResponse: can't find referenced class org.apache.http.client.methods.CloseableHttpResponse
Warning:org.springframework.http.client.HttpComponentsStreamingClientHttpRequest: can't find referenced class org.apache.http.impl.client.CloseableHttpClient
Warning:org.springframework.http.client.HttpComponentsStreamingClientHttpRequest: can't find referenced class org.apache.http.client.methods.CloseableHttpResponse
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.core.Persister
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.Root
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.Serializer
Warning:there were 100 unresolved references to classes or interfaces.
Warning:there were 2 unresolved references to program class members.
Warning:Exception while processing task java.io.IOException: Please correct the above warnings first.
Error:Execution failed for task ':myappApp:transformClassesAndResourcesWithProguardForMyappPublicRelease'.
Job failed, see logs for details
Information:BUILD FAILED
Information:Total time: 23.68 secs
Information:1 error
Information:59 warnings
Information:See complete output in console

It turns out that adding this to my proguard file fixed my issues.
-keepclassmembers class com.myapp.models.** {
*; }
-keep class com.fasterxml.jackson.annotation.** { *; }
-dontwarn com.fasterxml.jackson.databind.**
-dontwarn org.springframework.**
So in the end I could ignore most of those warnings after all. As I said simply ignoring them lead to crashes, which are fixed by not obfuscating jackson annotations and by not obfuscating my model classes which seem to be needed so that the json <--> pojo conversion can happen.

How to solve Can't find referenced class warnings when building for Amazon?

Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.
java.io.IOException: Please correct the above warnings first.
Here are the dependencies of my build.gradle
dependencies {
compile project(':chartboostSDK')
compile project(':flurry_lib')
compile project(':googleCloudMessaging_lib')
compile project(':mainLibProj')
compile project(':localytics_lib')
compile project(':mobihelp_sdk_android_v1534')
compile project(':unityandroidresources')
compile project(':iAB_lib')
compile project(':etcetera_lib')
compile 'com.google.code.gson:gson:2.3.1'
compile 'com.google.android.gms:play-services:+'
compile files('libs/FlurryPlugin.jar')
compile files('libs/FreshdeskPlugin.jar')
compile files('libs/Prime31UnityActivity.jar')
compile files('libs/adcolony-adapter-1.1.6.jar')
compile files('libs/android-bridge.jar')
compile files('libs/apsalar.jar')
compile files('libs/apsalarUnity3d.jar')
compile files('libs/bolts-android-1.2.1.jar')
compile files('libs/chartboost-adapter-1.0.6.jar')
compile files('libs/crittercism_v5_4_3_sdkonly.jar')
compile files('libs/dagger.jar')
compile files('libs/emojiplugin.jar')
compile files('libs/in-app-purchasing-2.0.61.jar')
compile files('libs/javax.inject.jar')
compile files('libs/mediationsdk-6.3.5.jar')
compile files('libs/nativex-adapter-1.0.3.jar')
compile files('libs/nineoldandroids.jar')
compile 'com.android.support:support-annotations:23.1.1'
compile files('libs/tapjoyconnectlibrary.jar')
compile files('libs/tapjoyunitywrapper.jar')
compile files('libs/unity-classes.jar')
compile files('libs/vungle-adapter-1.1.6.jar')
compile files('libs/unity-classes.jar')
}
Here is the list of warnings
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find superclass or interface com.google.android.gms.common.GooglePlayServicesClient$OnConnectionFailedListener
Warning:com.prime31.FlurryPlugin$2: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.prompt.PromptManager
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.hyprmx.HyprMXConfig
Warning:com.prime31.FlurryPlugin$6: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.prime31.FlurryPlugin$11: can't find referenced class com.flurry.android.FlurryAds
Warning:com.prime31.FlurryPlugin$12: can't find referenced class com.flurry.android.FlurryAds
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.context.ContextManager
Warning:com.amazon.device.iap.internal.b.c.b: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.prompt.SimplePrompt
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.task.TaskManager
Warning:com.amazon.device.iap.internal.b.b.b: can't find referenced method 'void preExecution()' in program class com.amazon.device.iap.internal.b.b.a
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.UnreadUpdatesCallback
Warning:com.amazon.device.iap.internal.b.b.b: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.MobihelpConfig
Warning:com.amazon.device.iap.internal.b.i: can't find superclass or interface com.amazon.android.framework.task.command.AbstractCommandTask
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.FeedbackType
Warning:com.amazon.device.iap.internal.b.h.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.common.GooglePlayServicesClient$OnConnectionFailedListener
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.unityads.UnityAdsConfig
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.flurry.FlurryConfig
Warning:com.prime31.FlurryPlugin$12: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.applovin.AppLovinConfig
Warning:com.amazon.device.iap.internal.b.e.d: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.prime31.FlurryPlugin: can't find referenced class com.flurry.android.FlurryAdListener
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.MobihelpConfig
Warning:com.prime31.FlurryPlugin: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.amazon.device.iap.internal.b.a.b: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.prompt.SimplePrompt
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.task.command.AbstractCommandTask
Warning:com.prime31.FlurryPlugin: can't find superclass or interface com.flurry.android.FlurryAdListener
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.location.LocationClient
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.Kiwi
Warning:com.amazon.device.iap.internal.b.e.c: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.hyprmx.HyprMXConfig
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.amazon.device.iap.internal.util.a: can't find referenced class com.amazon.android.Kiwi
Warning:com.prime31.FlurryPlugin$9: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.prime31.FlurryPlugin$10: can't find referenced class com.flurry.android.FlurryAds
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.resource.Resource
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.common.GooglePlayServicesClient$ConnectionCallbacks
Warning:com.tapjoy.internal.a$g: can't find referenced method 'void setLatestEventInfo(android.content.Context,java.lang.CharSequence,java.lang.CharSequence,android.app.PendingIntent)' in library class android.app.Notification
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.licensing.LicenseFailurePromptContentMapper
Warning:com.tapjoy.internal.ii: can't find referenced method 'org.apache.http.conn.ssl.SSLSocketFactory getHttpSocketFactory(int,android.net.SSLSessionCache)' in library class android.net.SSLCertificateSocketFactory
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find superclass or interface com.google.android.gms.common.GooglePlayServicesClient$ConnectionCallbacks
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.context.ContextManager
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.common.GooglePlayServicesClient$OnConnectionFailedListener
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.task.TaskManager
Warning:com.amazon.device.iap.internal.b.g.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.context.ContextManager
Warning:com.amazon.device.iap.internal.b.b.a$1: can't find referenced class com.amazon.android.framework.context.ContextManager
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.applovin.AppLovinConfig
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.licensing.LicenseFailurePromptContentMapper
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport$1: can't find superclass or interface com.freshdesk.mobihelp.UnreadUpdatesCallback
Warning:com.tapjoy.internal.km: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:com.prime31.FlurryPlugin$1: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.FeedbackType
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.Kiwi
Warning:com.prime31.FlurryPlugin$9: can't find referenced class com.flurry.android.FlurryAds
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.unityads.UnityAdsConfig
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.common.GooglePlayServicesClient
Warning:com.amazon.device.iap.internal.b.c.b: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport$1: can't find referenced class com.freshdesk.mobihelp.MobihelpCallbackStatus
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.Mobihelp
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.FailureResult
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.task.TaskManager
Warning:com.prime31.FlurryPlugin$7: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.supersonic.unity.androidbridge.AndroidBridge: can't find referenced class com.supersonic.adapters.flurry.FlurryConfig
Warning:com.prime31.FlurryPlugin$10: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.amazon.device.iap.internal.b.f: can't find referenced class com.amazon.android.framework.util.KiwiLogger
Warning:com.prime31.FlurryPlugin$10: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.vungle.publisher.location.GoogleLocationClientDetailedLocationProvider: can't find referenced class com.google.android.gms.common.GooglePlayServicesClient$ConnectionCallbacks
Warning:com.tapjoy.internal.ii$1: can't find referenced method 'org.apache.http.conn.ssl.SSLSocketFactory getHttpSocketFactory(int,android.net.SSLSessionCache)' in library class android.net.SSLCertificateSocketFactory
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.MobihelpConfig
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.FailureResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.licensing.LicenseFailurePromptContentMapper
Warning:com.prime31.FlurryPlugin$5: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.MobihelpConfig
Warning:com.amazon.device.iap.internal.b.a.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b.a$1: can't find superclass or interface com.amazon.android.framework.task.Task
Warning:com.amazon.device.iap.internal.b.d.d: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.g.a: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.amazon.device.iap.internal.b.c.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.task.pipeline.TaskPipelineId
Warning:com.amazon.device.iap.internal.b.f.a: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.tapjoy.internal.a$h: can't find referenced method 'void setLatestEventInfo(android.content.Context,java.lang.CharSequence,java.lang.CharSequence,android.app.PendingIntent)' in library class android.app.Notification
Warning:com.amazon.device.iap.internal.b.d.c: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.e.c: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.FailureResult
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.resource.Resource
Warning:com.prime31.FlurryPlugin$12: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.amazon.device.iap.internal.b.e.d: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.b.a$1: can't find referenced class com.amazon.android.framework.task.Task
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.Mobihelp
Warning:com.amazon.device.iap.internal.b.h.a: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.prime31.FlurryPlugin$9: can't find referenced class com.flurry.android.FlurryAdSize
Warning:com.prime31.FlurryPlugin$3: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.prime31.FlurryPlugin: can't find referenced class com.flurry.android.FlurryAdType
Warning:com.prime31.FlurryPlugin$4: can't find referenced class com.flurry.android.FlurryAgent
Warning:com.amazon.device.iap.internal.b.b: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.prime31.FlurryPlugin: can't find referenced class com.flurry.android.FlurryAds
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.task.pipeline.TaskPipelineId
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport: can't find referenced class com.freshdesk.mobihelp.FeedbackType
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.venezia.command.SuccessResult
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.task.command.AbstractCommandTask
Warning:com.amazon.device.iap.internal.b.b: can't find superclass or interface com.amazon.android.framework.prompt.SimplePrompt
Warning:com.amazon.device.iap.internal.b.b.a: can't find referenced class com.amazon.android.framework.resource.Resource
Warning:com.prime31.FlurryPlugin$8: can't find referenced class com.flurry.android.FlurryAds
Warning:com.freshdeskplugin.freshdesksupport.UnitySupport$1: can't find referenced class com.freshdesk.mobihelp.UnreadUpdatesCallback
Warning:com.amazon.device.iap.internal.b.b.a$1: can't find referenced class com.amazon.android.framework.context.ContextManager
Warning:com.amazon.device.iap.internal.b.d.b: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.prompt.PromptContent
Warning:com.amazon.device.iap.internal.b.c.a: can't find referenced class com.amazon.android.framework.exception.KiwiException
Warning:com.amazon.device.iap.internal.b.i: can't find referenced class com.amazon.android.framework.prompt.PromptManager
Warning:com.amazon.device.iap.internal.b.d.b: can't find referenced method 'void preExecution()' in program class com.amazon.device.iap.internal.b.i
Warning:there were 214 unresolved references to classes or interfaces.
You may need to add missing library jars or update their versions.
If your code works fine without the missing classes, you can suppress
the warnings with '-dontwarn' options.
Warning:there were 2 unresolved references to program class members.
(http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)
You may need to recompile the code.
Your input classes appear to be inconsistent.
Warning:there were 4 unresolved references to library class members.
You probably need to update the library versions.
Warning:Exception while processing task java.io.IOException: Please correct the above warnings first.
:starChef:transformClassesAndResourcesWithProguardForRelease FAILED

Normally Amazon suggests including the following in your ProGuard configuration file:
-dontwarn com.amazon.**
-keep class com.amazon.** {*;}
-keepattributes *Annotation*
and also skipping ProGuard's optimization:
-dontoptimize
However, in my personal experience, including suggestions from numerous other SO posts, none of that worked. In the end I had to turn off obfuscation (minifyEnabled false) to build for Amazon, which produced the release build:
android {
...
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'),
'proguard-rules.pro'
}
}
}
You may also want to experiment by adding this to your ProGuard settings:
-dontshrink
-keep class org.apache.** {*;}
-keepclasseswithmembernames class * {
native <methods>;
}

May be you are mismatching between
sdk version
Build Tools
Gradle Plugins
in terms of compatibility.
To resolve it, verify that you are using the latest versions of them. The gradle plugins are placed in the build.gradle of the project, and the other versions are on the build.gradle of the module.
For example, for SDK 23, you can use the Build Tools 23.0.1 and gradle plugins version 1.3.1.
clean it after change settings.

If you have several modules in your project, try to add
-dontwarn com.amazon.**
-keep class com.amazon.** {*;}
-keepattributes *Annotation*
-dontoptimize
to each proguard-rules.pro file in these modules.
For example, if you have two modules: base and installed, add the lines to both files:
base/proguard-rules.pro
installed/proguard-rules.pro

app:transformClassesAndResourcesWithProguardForRelease

Error:Execution failed for task
':app:transformClassesAndResourcesWithProguardForRelease'.
java.io.IOException: Please correct the above warnings first.
I have tried my best to find the solution but I did not get, whereas I found many questions.
Is there anything to ignore these warnings, I just want to generate a secure signed apk, therefore I have used minifyEnabled true
Message:
Warning:retrofit.client.OkClient$1: can't find superclass or interface com.squareup.okhttp.RequestBody
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Cache
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Call
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Response
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Response
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Cache
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Response
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Cache
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Request
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Call
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Response
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.CacheControl
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Response
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:com.squareup.picasso.OkHttpDownloader: can't find referenced class com.squareup.okhttp.Cache
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPMethod
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchServiceFactory
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPHeader
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPHeader
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPMethod
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPHeader
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPMethod
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchServiceFactory
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPMethod
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.URLFetchService
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPMethod
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPHeader
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPResponse
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPRequest
Warning:retrofit.appengine.UrlFetchClient: can't find referenced class com.google.appengine.api.urlfetch.HTTPHeader
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Call
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Response
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Response
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Headers
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Call
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Response
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Headers
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.OkHttpClient
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Request$Builder
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Response
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.RequestBody
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient: can't find referenced class com.squareup.okhttp.Headers
Warning:retrofit.client.OkClient$1: can't find referenced class com.squareup.okhttp.RequestBody
Warning:retrofit.client.OkClient$1: can't find referenced class okio.BufferedSink
Warning:retrofit.client.OkClient$1: can't find referenced class com.squareup.okhttp.RequestBody
Warning:retrofit.client.OkClient$1: can't find referenced class okio.BufferedSink
Warning:retrofit.client.OkClient$1: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient$1: can't find referenced class okio.BufferedSink
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.MediaType
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.ResponseBody
Warning:retrofit.client.OkClient$2: can't find referenced class com.squareup.okhttp.MediaType
Warning:rx.internal.util.unsafe.ConcurrentCircularArrayQueue: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.ConcurrentSequencedCircularArrayQueue: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.MpmcArrayQueueConsumerField: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.MpmcArrayQueueProducerField: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.SpmcArrayQueueConsumerField: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.SpmcArrayQueueProducerField: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.SpscArrayQueueConsumerField: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.SpscArrayQueueProducerFields: can't find referenced class sun.misc.Unsafe
Warning:rx.internal.util.unsafe.UnsafeAccess: can't find referenced class sun.misc.Unsafe

When you use ProGuard you have to always resolve all warnings to be able to process further with the build.
These warnings tell you that the libraries reference some code and there are no sources for that. That might and might not be ok. It depends if the problematic code ever get called.
In this case the libraries reference some code but the code doesn't seem to be ever called (e.g. because you didn't add some other library). In that case add -dontwarn rules to proguard-rules.pro file.
You use Retrofit and Picasso libraries. Try adding these rules:
-dontwarn okio.**
-dontwarn retrofit.**
-keep class retrofit.** { *; }
-keepclassmembers,allowobfuscation interface * {
#retrofit.http.** <methods>;
}
-dontwarn com.squareup.okhttp.**
It might fix your problem.
Note that you might experience further problems in runtime especially if any of those libraries use reflection and the code was shrunk and/or obfuscated. Then it's probable that you'll need more ProGuard rules for other libraries.
Edit:
To resolve RxJava related warnings add this dependency:
// ProGuard rules for RxJava
compile 'com.artemzin.rxjava:proguard-rules:1.1.1.0'
It adds necessary ProGuard rules for RxJava.

I had the same issue, and solved it by adding the following text to proguard-project.txt:
# for transformClassesAndResourcesWithProguardForRelease
# -- Picasso --
-dontwarn com.squareup.picasso.**
# -- OkHttp --
-dontwarn com.squareup.okhttp.internal.**
# -- Apache Commons --
-dontwarn org.apache.commons.logging.**
-ignorewarnings
-keep class *
{
public private *;
}

Proguard in Android Studio: Running proguardRelease complains of unresolved references

I'm trying to use Proguard for my release in Android Studio.
I have the classic problem that everyone has which is the "Unresolved references to classes or interfaces".
Like I read everywhere, I tried to add -dontwarn command to the proguard-project.txt file but it doesn't change anything.
Maybe my setup just ignore the proguard-project.txt file? Everything seems ok but I'm new to Android Studio, gradle and proguard so maybe I'm missing something! Any help is appreciated.
Here are my files:
proguard-project.txt
-dontwarn org.apache.**
project.properties
proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
# Project target.
target=android-15
android.library=false
Current warning I receive
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.X86Options
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.PowerPCOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.IA64Options
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.ARMOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.ARMThumbOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$1: can't find referenced class org.tukaani.xz.SPARCOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$BCJDecoder: can't find referenced class org.tukaani.xz.FilterOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$BCJDecoder: can't find referenced class org.tukaani.xz.FinishableWrapperOutputStream
Warning:org.apache.commons.compress.archivers.sevenz.Coders$BCJDecoder: can't find referenced class org.tukaani.xz.FilterOptions
Warning:org.apache.commons.compress.archivers.sevenz.Coders$BCJDecoder: can't find referenced class org.tukaani.xz.FinishableOutputStream
Warning:org.apache.commons.compress.archivers.sevenz.Coders$LZMADecoder: can't find referenced class org.tukaani.xz.LZMAInputStream
Warning:org.apache.commons.compress.archivers.sevenz.DeltaDecoder: can't find referenced class org.tukaani.xz.DeltaOptions
Warning:org.apache.commons.compress.archivers.sevenz.DeltaDecoder: can't find referenced class org.tukaani.xz.FinishableWrapperOutputStream
Warning:org.apache.commons.compress.archivers.sevenz.DeltaDecoder: can't find referenced class org.tukaani.xz.DeltaOptions
Warning:org.apache.commons.compress.archivers.sevenz.DeltaDecoder: can't find referenced class org.tukaani.xz.UnsupportedOptionsException
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.LZMA2Options
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.LZMA2InputStream
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.FinishableWrapperOutputStream
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.LZMA2Options
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.FinishableOutputStream
Warning:org.apache.commons.compress.archivers.sevenz.LZMA2Decoder: can't find referenced class org.tukaani.xz.LZMA2Options
Warning:org.apache.commons.compress.compressors.lzma.LZMACompressorInputStream: can't find referenced class org.tukaani.xz.LZMAInputStream
Warning:org.apache.commons.compress.compressors.xz.XZCompressorInputStream: can't find referenced class org.tukaani.xz.XZ
Warning:org.apache.commons.compress.compressors.xz.XZCompressorInputStream: can't find referenced class org.tukaani.xz.XZInputStream
Warning:org.apache.commons.compress.compressors.xz.XZCompressorInputStream: can't find referenced class org.tukaani.xz.SingleXZInputStream
Warning:org.apache.commons.compress.compressors.xz.XZCompressorInputStream: can't find referenced class org.tukaani.xz.XZ
Warning:org.apache.commons.compress.compressors.xz.XZCompressorOutputStream: can't find referenced class org.tukaani.xz.XZOutputStream
Warning:org.apache.commons.compress.compressors.xz.XZCompressorOutputStream: can't find referenced class org.tukaani.xz.LZMA2Options
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Warning:org.codehaus.jackson.map.ext.DOMSerializer: can't find referenced class org.w3c.dom.bootstrap.DOMImplementationRegistry
Warning:org.joda.time.DateMidnight: can't find referenced class org.joda.convert.FromString
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Warning:org.joda.time.YearMonth: can't find referenced class org.joda.convert.ToString
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Warning:org.joda.time.Years: can't find referenced class org.joda.convert.ToString
Warning:org.joda.time.base.AbstractDuration: can't find referenced class org.joda.convert.ToString
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Warning:org.springframework.http.client.CommonsClientHttpRequest: can't find referenced class org.apache.commons.httpclient.HttpMethodBase
Warning:org.springframework.http.client.CommonsClientHttpRequest: can't find referenced class org.apache.commons.httpclient.URI
Warning:org.springframework.http.client.CommonsClientHttpRequest: can't find referenced class org.apache.commons.httpclient.URIException
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Warning:org.springframework.http.client.CommonsClientHttpRequest: can't find referenced class org.apache.commons.httpclient.methods.EntityEnclosingMethod
Warning:org.springframework.http.client.CommonsClientHttpRequest: can't find referenced class org.apache.commons.httpclient.methods.RequestEntity
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpClient
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.MultiThreadedHttpConnectionManager
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpClient
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpConnectionManager
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.params.HttpConnectionManagerParams
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.GetMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.DeleteMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.HeadMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.OptionsMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.PostMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.PutMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.methods.TraceMethod
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.MultiThreadedHttpConnectionManager
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpConnectionManager
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.params.HttpConnectionManagerParams
Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpClient
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Warning:org.springframework.http.client.CommonsClientHttpRequestFactory: can't find referenced class org.apache.commons.httpclient.HttpConnectionManager
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.HttpMethod
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.Header
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.HttpMethod
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.Header
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.HttpMethod
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.Header
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.HttpMethod
Warning:org.springframework.http.client.CommonsClientHttpResponse: can't find referenced class org.apache.commons.httpclient.Header
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedInput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedOutput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedInput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedOutput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedInput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.WireFeedOutput
Warning:org.springframework.http.converter.feed.AbstractWireFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.WireFeed
Warning:org.springframework.http.converter.feed.AtomFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.atom.Feed
Warning:org.springframework.http.converter.feed.RssChannelHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.rss.Channel
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedInput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedOutput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedInput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedOutput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedInput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.FeedException
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.io.SyndFeedOutput
Warning:org.springframework.http.converter.feed.SyndFeedHttpMessageConverter: can't find referenced class com.google.code.rome.android.repackaged.com.sun.syndication.feed.synd.SyndFeed
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.ObjectMapper
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonFactory
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonGenerator
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.ObjectMapper
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonEncoding
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.JavaType
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonEncoding
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonGenerator
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonEncoding
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonFactory
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonGenerator
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Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.ObjectMapper
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.JavaType
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonEncoding
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonGenerator
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.databind.JavaType
Warning:org.springframework.http.converter.json.MappingJackson2HttpMessageConverter: can't find referenced class com.fasterxml.jackson.core.JsonEncoding
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.core.Persister
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.Root
Warning:org.springframework.http.converter.xml.SimpleXmlHttpMessageConverter: can't find referenced class org.simpleframework.xml.Serializer
Warning:there were 276 unresolved references to classes or interfaces.
You may need to add missing library jars or update their versions.
If your code works fine without the missing classes, you can suppress
the warnings with '-dontwarn' options.
(http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)

Experience here is coming from Eclipse and not Android Studio. I will typically have my proguard.cfg file in a location at the root level with the project. And the line inside my project.properties referencing the file would look something like this:
proguard.config=proguard.cfg
while you have this:
proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
Do you also have a file names proguard-android.txt? I am unfamiliar with the style convention there in your command line. Perhaps it is a matter of not finding the right file?