Cargo Features

[dependencies]
userror = { version = "0.1.0", default-features = false, features = ["colour"] }
default = colour

The colour feature is set by default whenever userror is added without default-features = false somewhere in the dependency tree.

colour default = ansi_term

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.

ansi_term colour

Enables ansi_term ^0.7