use std::env;
use std::ffi::OsString;
use std::process::Command;
fn main() {
println!("cargo:rerun-if-changed=build.rs");
let rustc = env::var_os("RUSTC").unwrap_or_else(|| OsString::from("rustc"));
let output = Command::new(rustc)
.arg("--version")
.output()
.expect("failed to run `rustc --version`");
if String::from_utf8_lossy(&output.stdout).contains("nightly") {
println!("cargo:rustc-cfg=nightly");
}
}