Cargo Features

bevy_mod_ffi_guest has no features set by default.

[dependencies]
bevy_mod_ffi_guest = { version = "0.2.0", features = ["macros"] }
macros = bevy_mod_ffi_macros

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

bevy_mod_ffi_macros macros?