Question No longer possible to use define symbols around serialized classes

I have a setup for several scripts where they're wrapped in a define symbol. This is to ensure no compilation errors are thrown for their base class, if it is not present, but still allowing it to be serialized. Like so:

Code (CSharp):

1. #if !POST_PROCESSING_INSTALLED
2.     public class PostEfectSettings : ScriptableObject {}
3. #else
4.     [Serializable]
5.     [PostProcess(typeof(EffectRenderer), PostProcessEvent.AfterStack, "Post processing effect", true)]
6.     public sealed class PostEfectSettings : PostProcessEffectSettings
7.     {
8.     }
9. #endif

This has worked up to 2019.3, but since 2020.1 the following warning will be thrown:

The result is that the ScriptableObject cannot be serialized, as if the file and class name mismatch.

What is the reason for enforcing this? Do I now need two "PostEfectSettings" files, where one is compiled out and the other one isn't?

 

Have you tried defining them in different files? Does that work?

 

Thanks for your answer. Does "currently" mean "it's just for now, we're going to fix it during 2020.1 beta cycle"?

In order to make serialization work, UnityEngine.Object derived classes must live in a file that uses the class name as filename. Storing those classes in separate files would then require them to be placed in different folders, because the file system does not allow to have files with identical filenames in the same folder.

It doesn't sound like an attractive long-term workaround for me.