Import module from parent directory

So I have a package which used to have one binary, but now I want to add a second binary. The file structure is

src
 |- main.rs
 |- extra.rs
 \- bin
     \- new_bin.rs

Both main and new_bin need to call functions in extra.rs. In main.rs I can say mod extra and use extra to import that module, but I can't figure out how to access extra from new_bin.rs. I tried mucking around with ::extra, crate::extra or super::extra but the compiler doesn't like any of those.

If the point of package are the binaries and everything else is just shared support for those binaries,

src
 |- lib.rs // was extra.rs
 \- bin
     |- bin_one.rs // was main.rs
     |- bin_two.rs // was new_bin.rs

And in Cargo.toml

[[bin]]
name = "bin_one"
[[bin]]
name = "bin_two"

And to use the shared code, if your package is called foo,

use foo::extra_stuff;
fn main() {
    extra_stuff();
}