Function declared_by 

pub fn declared_by(
    catalog: &Catalog,
    id: RuntimeId,
) -> Result<Vec<OptionDecl>, String>

What superfluid runtime options <id> lists: a usable runtime’s declaration, else the one its adapter makes before an install, asked as runtime versions asks it (the worker named for it, the linked adapter, the worker that would install it): the options, --llamacpp-lib among them, are what one reads before the runtime runs here.