rust/tests/ui/proc-macro/env.rs

//@ aux-build:env.rs
//@ run-pass
//@ rustc-env: THE_CONST=1
//@ compile-flags: -Zunstable-options --env-set THE_CONST=12 --env-set ANOTHER=4

#![crate_name = "foo"]

extern crate env;

use env::generate_const;

generate_const!();

fn main() {
    assert_eq!(THE_CONST, 12);
    assert_eq!(ANOTHER, 1);
}