Potentially related to #2180. It's basically inverse of this issue. What I'm seeing is that the generated code from KSP is mangled$library_debug while the Kotlin compiler creates mangled$library instead. This can be fixed by setting android.builtInKotlin=false. I believe this to be an AGP issue with builtin Kotlin, but filing a ticket here as well just in case. AGP bug issue: https://issuetracker.google.com/issues/458762165