Missing Proguard rules? Crash at 'java.lang.NoSuchFieldException: No field result in class Lkotlin/f/i;'

[fightyz]

I'm using Kotlin coroutine 1.3.2, and my app is obfuscated. When I using coroutines, I get the following crash stack：

java.lang.RuntimeException: java.lang.NoSuchFieldException: No field result in class Lkotlin/f/i;
java.util.concurrent.atomic.AtomicReferenceFieldUpdater$AtomicReferenceFieldUpdaterImpl.<init>(AtomicReferenceFieldUpdater.java:338)
	at java.util.concurrent.atomic.AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdater.java:109)
	at kotlin.coroutines.SafeContinuation.<clinit>(SourceFile:31)

According to the mapping file, the class Lkotlin/f/i is actually SafeContinuation. I look into SafeContinuation, there is a field named result, and it is volatile.

I also noticed that the Kotlin extension library's proguard file has kept all volatile field. So I guess it is also necessary to keep all volatile in Kotlin's stdlib?