Cargo Features

[dependencies]
gd32f3x0-pac = { version = "0.1.0", default-features = false, features = ["rt"] }
default = rt

The rt feature is set by default whenever gd32f3x0-pac is added without default-features = false somewhere in the dependency tree.

rt default

Enables device of cortex-m-rt

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.

cortex-m-rt rt