Kotlin reflect proguard SmallSortedMap

Question

Warning: kotlin.reflect.jvm.internal.KClassImpl: can't find referenced class kotlin.reflect.jvm.internal.KClassImpl$kotlin.reflect.jvm.internal.KClassImpl$Data
Warning: kotlin.reflect.jvm.internal.KClassImpl: can't find referenced class kotlin.reflect.jvm.internal.KClassImpl$kotlin.reflect.jvm.internal.KClassImpl$Data
Warning: kotlin.reflect.jvm.internal.KClassImpl$data$1: can't find referenced class kotlin.reflect.jvm.internal.KClassImpl$kotlin.reflect.jvm.internal.KClassImpl$Data
Warning: kotlin.reflect.jvm.internal.KClassImpl$data$1: can't find referenced class kotlin.reflect.jvm.internal.KClassImpl$kotlin.reflect.jvm.internal.KClassImpl$Data
Warning: kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap: can't find referenced class kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$Entry
Warning: kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap: can't find referenced class kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$EntrySet
Warning: kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$Entry: can't find referenced class kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$Entry
Warning: kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$Entry: can't find referenced class kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$kotlin.reflect.jvm.internal.impl.protobuf.SmallSortedMap$Entry

I'm getting these warnings which break my release build on the task transformClassesAndResourcesWithProguardForAppRelease.

I know I can just ignore the warnings or inform proguard to not warn by using -dontwarn but I was wondering if anyone else had come across this and had actually found the correct fix.

I'm using Kotlin version 1.1.4-2

Answer 1

Quoting Alexander Udalov from issue KT-7652:

In any way, reflection failures when kotlin.* is obfuscated are expected at the moment. What we can do is work on a useful set of rules for proguard to minimize the binary size of the reflection library.

So there is no correct fix at the moment.