use std::env::var_os;
use std::process::Command;
fn main() {
if is_nightly() {
println!("cargo:rustc-cfg=nightly")
}
}
fn is_nightly() -> bool {
if let Some(version) = rust_version() {
version.contains("nightly") || version.contains("dev")
} else {
false
}
}
fn rust_version() -> Option<String> {
let rustc = var_os("RUSTC")?;
let output = Command::new(rustc).arg("--version").output().ok()?;
String::from_utf8(output.stdout).ok()
}