Function install_contract_hazards 

pub unsafe fn install_contract_hazards(
    executor: *mut c_void,
    hazards: &'static [HazardSpec],
)

phase-462 W3b – install a contracted Rust image’s hazard table on one executor, after install_contract_monitors (each hazard’s guards index the two tables that call installs). nros::main! emits this only for an executor whose tables observe a hazard; the observer then reports hazard-detected, hazard-reaction and hazard-recovered through the reporter that call armed.

A NULL or non-executor handle installs nothing: the monitor install it follows has already refused that handle, and said so.

Safety

As for install_contract_monitors.