From our customer working in Preview 2:
Steps to reproduce:
1. I package the plugin
2. Place packaged plugin inside the engine's plugins directory (Engine/Plugins/Runtime).
3. Create a new project and enable the new plugin inside it
4. Try Packaging the project
It fails with this error message:
UATHelper: Packaging (Windows): ERROR: Expecting to find a type to be declared in a module rules named 'CoolPlugin' in UE5Rules, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null. This type must derive from the 'ModuleRules' type defined by Unreal Build Tool.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-146234 in the post.