wasmer/lib/cli/build.rs

use chrono::prelude::*;
use std::process::Command;

pub fn main() {
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-env-changed=WASMER_INSTALL_PREFIX");

    // Set WASMER_GIT_HASH
    let git_hash = Command::new("git")
        .args(&["rev-parse", "HEAD"])
        .output()
        .ok()
        .and_then(|output| String::from_utf8(output.stdout).ok())
        .unwrap_or_default();
    println!("cargo:rustc-env=WASMER_BUILD_GIT_HASH={}", git_hash);

    if git_hash.len() > 5 {
        println!(
            "cargo:rustc-env=WASMER_BUILD_GIT_HASH_SHORT={}",
            &git_hash[..5]
        );
    }

    let utc: DateTime<Utc> = Utc::now();
    let date = utc.format("%Y-%m-%d").to_string();
    println!("cargo:rustc-env=WASMER_BUILD_DATE={}", date);
}