ProGuard not working with okhttp

Question

ProGuard won't play nice with okhttp and I keep getting the following Warnings:

Warning:com.squareup.okhttp.internal.huc.HttpsURLConnectionImpl: can't find referenced method 'long getContentLengthLong()' in program class com.squareup.okhttp.internal.huc.HttpURLConnectionImpl
Warning:com.squareup.okhttp.internal.huc.HttpsURLConnectionImpl: can't find referenced method 'long getHeaderFieldLong(java.lang.String,long)' in program class com.squareup.okhttp.internal.huc.HttpURLConnectionImpl
Warning:com.squareup.okhttp.internal.huc.JavaApiConverter$CacheHttpsURLConnection: can't find referenced method 'long getContentLengthLong()' in program class com.squareup.okhttp.internal.huc.JavaApiConverter$CacheHttpURLConnection
Warning:com.squareup.okhttp.internal.huc.JavaApiConverter$CacheHttpsURLConnection: can't find referenced method 'long getHeaderFieldLong(java.lang.String,long)' in program class com.squareup.okhttp.internal.huc.JavaApiConverter$CacheHttpURLConnection
Warning:there were 4 unresolved references to program class members.
         Your input classes appear to be inconsistent.
         You may need to recompile the code.
         (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedprogramclassmember)

These are my proguard settings for okhttp and retrofit:

-dontwarn rx.**

-dontwarn okio.**

-dontwarn com.squareup.okhttp.*

-dontwarn retrofit.appengine.UrlFetchClient


-keep class retrofit.** { *; }

-keepclasseswithmembers class * {

@retrofit.http.* <methods>; }

-keepattributes Signature 
-keepattributes *Annotation*

Could this have something to do with the changes to ProGuard in Android Studio 1.0?

I tried the answers to related questions but they only suggested to use the settings I already have.

Answer 1

This works for me:

You have to add to your proguard-rules.pro this two lines:

-keep class com.squareup.okhttp.** { *; }

-keep interface com.squareup.okhttp.** { *; }

---

Complete proguard-rules.pro file will look like:

-dontwarn rx.**

-dontwarn okio.**

-dontwarn com.squareup.okhttp.**
-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }

-dontwarn retrofit.**
-dontwarn retrofit.appengine.UrlFetchClient
-keep class retrofit.** { *; }
-keepclasseswithmembers class * {
    @retrofit.http.* <methods>;
}

-keepattributes Signature
-keepattributes *Annotation*

Source: https://stackoverflow.com/a/24178851/4102045