Issues with Android R8

[ToxicBakery]

Android R8 seems to cause pain on release builds. In our use case we had a lot of type parameter errors that look like this

java.lang.IllegalArgumentException: Class declares 0 type parameters, but 1 were provided.
                 	at kotlin.reflect.full.KClassifiers.createType(SourceFile:53)
                 	at kotlin.reflect.jvm.internal.CachesKt.getOrCreateKTypeWithTypeArguments(SourceFile:69)
                 	at kotlin.reflect.jvm.internal.CachesKt.getOrCreateKType(SourceFile:58)
                 	at kotlin.reflect.jvm.internal.ReflectionFactoryImpl.typeOf(SourceFile:123)
                 	at kotlin.jvm.internal.Reflection.typeOf(SourceFile:133)

In proguard-rules.pro this configuration resolves the issue but it could likely be improved to target the specific classes relevant to the problem.

-keep class de.jensklingenberg.ktorfit.** { *; }
-keepclassmembers class de.jensklingenberg.ktorfit.** { *; }

I did not see documentation for this issue and the other proguard related issue seems to be about reflect itself and not the issue we had.