Good morning Herbert!
You already know this, as the downloadable code has corrected it already:
- On page 92, you define the enum GamePhase. This has a number of traits derived, but is missing the Copy trait. Without this, a rather cryptic error message results when running the code later in the chapter (specifically when modifying the build() function).
- The other change between the book code and the downloadable code: On p93, you add the gameStatePlugin:
.add_plugins(GameStatePlugin::<GamePhase>::new( GamePhase::MainMenu, // ... )
In the downloadable code, this call is just .add_plugin(GameStatePlugin::new(
I am not (yet) sure if this second change is an issue or not - I am going to go and play a bit to see what happens!