Cargo Features

[dependencies]
online = { version = "4.0.2", default-features = false, features = ["tokio-runtime", "sync-runtime"] }
default = sync-runtime

The sync-runtime feature is set by default whenever online is added without default-features = false somewhere in the dependency tree.

tokio-runtime = tokio

Affects online::tokio…

sync-runtime default

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.

tokio tokio-runtime?