Lombok is a Java annotation library that generates code during compilation (like getters, setters, builders, etc.). Once the code is compiled, Lombok's job is done, it's not needed at runtime. The Ably library includes Lombok as a compileOnly dependency, so the annotations are available during build but aren't packaged into the final library.

When R8/ProGuard analyses the bytecode, it sees references to lombok.Generated and other Lombok classes, but those classes don't exist in the runtime classpath (because they were intentionally excluded). This triggers the "Missing class" warning.

So excluding Lombok from ProGuard/R8 warnings like you have said will resolve this.