Exception "java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType" launching Plaid handler when proguard/minify is enabled.

[vince-vendant]

Repro

Kotlin app, build with:

        isMinifyEnabled = true

When this function is called

                    linkAccountToPlaid.launch(plaidHandler)

before a plaid UI appears, I see this exception.

java.lang.ClassCastException: java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType
retrofit2.HttpServiceMethod.parseAnnotations(SourceFile:46)
retrofit2.ServiceMethod.parseAnnotations(SourceFile:39)
retrofit2.Retrofit.loadServiceMethod(SourceFile:202)
retrofit2.Retrofit$1.invoke(SourceFile:160)
java.lang.reflect.Proxy.invoke(Proxy.java:1006)
$Proxy3.a(Unknown Source)
com.plaid.internal.v4$a.invokeSuspend(SourceFile:6)
kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(SourceFile:33)
kotlinx.coroutines.DispatchedTask.run(SourceFile:108)
kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(SourceFile:115)
kotlinx.coroutines.scheduling.TaskImpl.run(SourceFile:103)
kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(SourceFile:584)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(SourceFile:793)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(SourceFile:697)
kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(SourceFile:684)
Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@f8e6efb, Dispatchers.Default]

Environment

Android OS Version	e.g. 15.0.0 (35)
Android Devices/Emulators	e.g. Pixel 9 Pro XL physical

Additional Info

Adding these lines to my proguard-rules.pro fixed the issue.

# Keep generic signature of Call, Response (R8 full mode strips signatures from non-kept items).
-keep,allowobfuscation,allowshrinking interface retrofit2.Call
-keep,allowobfuscation,allowshrinking class retrofit2.Response

# With R8 full mode generic signatures are stripped for classes that are not
# kept. Suspend functions are wrapped in continuations where the type argument
# is used.
-keep,allowobfuscation,allowshrinking class kotlin.coroutines.Continuation

[vince-vendant]

Credit: https://stackoverflow.com/a/77300397/30672