Cargo Features

[dependencies]
utf8-tokio = { version = "0.2.1", default-features = false, features = ["tracing"] }
default = tracing

The tracing feature is set by default whenever utf8-tokio is added without default-features = false somewhere in the dependency tree.

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.

tracing default