build.rs

use std::{env, path::PathBuf};

use vergen::{generate_cargo_keys, ConstantsFlags};

const ERROR_MSG: &str = "Failed to generate metadata files";

fn main() {
    generate_cargo_keys(ConstantsFlags::SHA_SHORT).expect(ERROR_MSG);

    let mut manifest_dir = PathBuf::from(
        env::var("CARGO_MANIFEST_DIR").expect("`CARGO_MANIFEST_DIR` is always set by cargo."),
    );

    while manifest_dir.parent().is_some() {
        if manifest_dir.join(".git/HEAD").exists() {
            println!(
                "cargo:rerun-if-changed={}",
                manifest_dir.join(".git/HEAD").display()
            );
            return;
        }

        manifest_dir.pop();
    }

    println!("cargo:warning=Could not find `.git/HEAD` from manifest dir!");
}