Nonworking Rust

mod.rs

mod tu1;

fn main() {
	println!("Hello World");
	tu1::fun1();
}

tu1.rs

mod tu2;

pub fn fun1() {
	println!("fun1()");
	::tu2::fun2();
}

tu2.rs

pub fn fun2() {
	println!("fun2()");
}

$ rustc mod.rs
tu1.rs:2:5: 2:8 error: cannot declare a new module at this location
tu1.rs:2 mod tu2;
^~~
tu1.rs:2:5: 2:8 note: maybe move this module tu1 to its own directory via tu1/mod.rs
tu1.rs:2 mod tu2;
^~~
tu1.rs:2:5: 2:8 note: ... or maybe use the module tu2 instead of possibly redeclaring it
tu1.rs:2 mod tu2;
^~~

Looks like Rust is trying to enforce a certain directory structure to your modules. Does http://thread.gmane.org/gmane.comp.lang.rust.devel/10032 help?