Cargo Features

[dependencies]
swc-plugin-inferno = { version = "0.0.20", default-features = false, features = ["concurrent", "serde-impl"] }
default = serde-impl

The serde-impl feature is set by default whenever swc-plugin-inferno is added without default-features = false somewhere in the dependency tree.

concurrent = rayon
serde-impl default = serde

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.

rayon concurrent?
serde serde-impl