Cargo Features

labelled-enum has no features set by default.

labelled-enum = { version = "0.1.1", features = ["serde_plugin"] }
serde_plugin = serde

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.

serde serde_plugin?

Affects labelled-enum::serde_plugin