Cargo Features

ages-ice-archive = { version = "0.3.2", default-features = false, features = ["oodle"] }
default = oodle

The oodle feature is set by default whenever ages-ice-archive is added without default-features = false somewhere in the dependency tree.

oodle default = cc

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features.

cc build oodle