Function install_contract_modes 

pub unsafe fn install_contract_modes(
    executor: *mut c_void,
    modes: &'static [ModeTables],
) -> Result<(), &'static str>

phase-462 W4 – install a contracted Rust image’s MODE variants of the two monitor tables on one executor, after install_contract_monitors (entry 0 of modes is that call’s base tables). nros::main! emits this only for a model that declares modes; nros::monitor::request_mode then switches every executor at its next spin.

Errors

A variant whose tables are not the base’s length, which the bake already refuses, so this is a corrupted image; a NULL or non-executor handle, as install_contract_monitors reports it.

Safety

As for install_contract_monitors.