The Cargo.toml file gives the answer: https://github.com/Shopify/ruby/blob/rust-yjit-upstreaming/yjit/Cargo.toml#L21 https://github.com/Shopify/ruby/blob/rust-y

The Cargo.toml file gives the answer: https://github.com/Shopify/ruby/blob/rust-yjit-upstreaming/yjit/Cargo.toml#L21 https://github.com/Shopify/ruby/blob/rust-yjit-upstreaming/y... There is only a single, optional dependency which is apparently only used for testing.