Cargo Features

[dependencies]
sha2raw = { version = "12.0.0", default-features = false, features = ["asm"] }
default = asm

The asm feature is set by default whenever sha2raw is added without default-features = false somewhere in the dependency tree.

asm default = sha2-asm

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.

sha2-asm asm