Macro set_error 

macro_rules! set_error {
    ($code:expr, $($msg_args:tt)+) => { ... };
}

Set the last error.

Example:

let reason = "just 'cause";
tarantool::set_error!(TarantoolErrorCode::Unsupported, "this you cannot do, because: {reason}");
return Err(BoxError::last());