You have to see https://github.com/adnanademovic/rosrust/tree/master/examples instead of this.
Tutorial code of rosrust.
$ cargo build$ roscore$ cargo run --bin publisheror,
$ ./target/debug/publisher$ cargo run --bin subscriberor
$ ./target/debug/subscriberAdd more message to build.rs.
#[macro_use]
extern crate rosrust;
rosmsg_main!("std_msgs/String", "more_msgs/SomeMsg");then, you can use msg::more_msgs::SomeMsg in the sample code.