Cargo Features

[dependencies]
serde_item = { version = "0.2.0", default-features = false, features = ["with-syntex", "nightly-testing"] }
default = with-syntex

The with-syntex feature is set by default whenever serde_item is added without default-features = false somewhere in the dependency tree.

with-syntex default = syntex_syntax
nightly-testing = clippy

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.

clippy nightly-testing?
syntex_syntax with-syntex

Enables syntex_syntax ^0.36.0