Exception during serializing of subclass of abstract class in Kotlin/MPP

[and-marsh]

Describe the bug Hi, i have a Kotlin/MPP project with iOS, Android and macOS targets. When I tried to implement example from here, I got an exception for macOs and iOS:

kotlinx.serialization.SerializationException: Serializer for class 'Project' is not found.
Mark the class as @Serializable or provide the serializer explicitly.

For Android it works fine:

{"type":"owned","name":"kotlinx.coroutines","owner":"kotlin"}

To Reproduce My build.gradle and code is attached SerializableTest.kts is from commonMain dir, CommonTest.kts - from commonTest dir. Tests were started via gradle tasks iosX64Test and macosX64Test

Expected behavior Succesful serialization on macOS and iOS like this:

{"type":"owned","name":"kotlinx.coroutines","owner":"kotlin"}

Environment

• Kotlin version: 1.4.0
• Library version: 1.0.0-RC
• Kotlin platforms: iOS, Android and macOS
• Gradle version: 6.5
• Other relevant context: macOS Catalina 10.15.5

[qwwdfsad]

Thanks for the self-contained reproducer! See the response and potential workarounds here: https://github.com/Kotlin/kotlinx.serialization/issues/1000#issuecomment-678983701

Closing as duplicate of #1000

[and-marsh]

Thanks a lot!