use std::env;
use std::process::Command;
use std::str;
fn main() {
let compiler = match rustc_version() {
Some(compiler) => compiler,
None => return,
};
if compiler.nightly {
println!("cargo:rustc-cfg=backtrace");
}
}
struct Compiler {
nightly: bool,
}
fn rustc_version() -> Option<Compiler> {
let rustc = match env::var_os("RUSTC") {
Some(rustc) => rustc,
None => return None,
};
let output = match Command::new(rustc).arg("--version").output() {
Ok(output) => output,
Err(_) => return None,
};
let version = match str::from_utf8(&output.stdout) {
Ok(version) => version,
Err(_) => return None,
};
Some(Compiler {
nightly: version.contains("nightly") || version.contains("dev"),
})
}