You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: build.rs
    path of file: ./repos/some-tank-game-rs
    
    the code of the file until where you have to start completion: use chrono::prelude::*;
use std::process::Command;

fn main() {
    let output = Command::new("git").args(&["rev-parse", "--short", "HEAD"]).output().unwrap();
    let gi
    
fn main() {
    let output = Command::new("git").args(&["rev-parse", "--short", "HEAD"]).output().unwrap();
    let git_hash = String::from_utf8(output.stdout).unwrap();

    let build_date = Utc::now();
    println!("cargo:rustc-env=GIT_HASH={}", git_hash);
    println!("cargo:rustc-env=BUILD_DATE={}", build_date.date());
}