Cargo Features

[dependencies]
private-gemm-x86 = { version = "0.1.11", default-features = false, features = ["rayon"] }
default = rayon

The rayon feature is set by default whenever private-gemm-x86 is added without default-features = false somewhere in the dependency tree.

rayon default

Enables crossbeam, rayon, and spindle

private-gemm-x86 has 2 features without comments.