build.rs

use std::fs::File;
use std::io::Write;
use std::process::Command;
use std::str::from_utf8;

fn main() {
    let mut f = File::create("src/release.rs").unwrap();

    {
        let hash = match Command::new("git")
            .arg("show-ref")
            .arg("--head")
            .arg("--hash=8")
            .output() {
                Ok(o) => String::from(from_utf8(&o.stdout[0..8]).unwrap()),
                Err(_) => String::from("00000000"),
            };
        write!(f, "pub const GIT_SHA1: &'static str = \"{}\";\n", &hash[0..8]).unwrap();
    }

    {
        let dirty = match Command::new("git")
            .arg("diff")
            .arg("--no-ext-diff")
            .output() {
                Ok(o) => o.stdout.len() > 0,
                Err(_) => true,
            };
        write!(f, "pub const GIT_DIRTY: bool = {};\n", if dirty { "true" } else { "false "}).unwrap();
    }

    {
        let version = match Command::new("rustc")
            .arg("--version")
            .output() {
                Ok(o) => String::from(from_utf8(&o.stdout).unwrap().trim()),
                Err(_) => String::new(),
            };
        write!(f, "pub const RUSTC_VERSION: &'static str = {:?};\n", version).unwrap();
    }
}