Linking against hyper on both OS X and Linux

Cargo.toml

[package]
name = "http"
version = "0.1.0"
authors = ["Marius Seritan <github@seritan.net>"]

[target.'cfg(target_os = "macos")'.dependencies]
hyper = {version="*", default_features=false, features=["security-framework"]}

[target.'cfg(target_os = "linux")'.dependencies]
hyper = {version="*"}

src main.rs

extern crate hyper;

fn main() {
    let client = hyper::Client::new();
    println!("Hello, world!");
}