New proguard rules broke inner classes

[natario1]

Describe the bug
We picked serialization recently in a new project, so we're using the new proguard rules introduced with #1721 . With them, we get: "Serializer for class 'Foo' is not found.".
This does not happen with the previous rules.

To Reproduce
Foo is an inner data class:

object ApiResponses {
   @Serializable data class Foo(...)
   @Serializable data class Bar(...)
}

I can look into compiled files if needed. It's hard to debug without knowing the internals, e.g. what fields are expected to be where.

[natario1]

As a side request, I have spent too much time trying to debug the issue on the wrong Foo class. It would help if the error message included the qualified class name, or at least ApiResponses.Foo instead of just Foo for inner classes.

[shanshin]

Hi,
instead of the rule

# Keep `serializer()` on companion objects (both default and named) of serializable classes.
-if @kotlinx.serialization.Serializable class ** {
    static **$* *;
}
-keepclassmembers class <1>$<3> {
    kotlinx.serialization.KSerializer serializer(...);
}

try to use

# Keep `serializer()` on companion objects (both default and named) of serializable classes.
-if @kotlinx.serialization.Serializable class ** {
    static **$* *;
}
-keepclassmembers class <2>$<3> {
    kotlinx.serialization.KSerializer serializer(...);
}

[natario1]

Hi,
I can try when I have time for this, likely many weeks from now. We're using the old rules successfully, and generally after several years of development, proguard directives are still incomprehensible to me, so the less I touch it, the better. I think I'm not alone in this, so it's important to have robust official rules, I appreciate your work on this.