Workspaces are introduced as a new concept that is not part of Hands-on Rust. In the “hello_bevy” intro to workspaces section we add a dependency to bevy:

# more_hands/hello_bevy/Cargo.toml
[dependencies]
bevy = { workspace = true }

And then the book goes on assuming that hello_bevy will install and run as shown. However we are missing the step to include the dependency in the workspace itself:

# more_hands/Cargo.toml
[workspace.dependencies]
bevy = "0.15"