Cargo Features

[dependencies]
global_counter = { version = "0.2.2", default-features = false, features = ["parking_lot"] }
default = parking_lot

The parking_lot feature is set by default whenever global_counter 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.

parking_lot default

Enables parking_lot ^0.11.1

Prior to 1.0.0, even patch bumps can break compatibility.