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/vim-clap/crates/maple
    
    the code of the file until where you have to start completion: use std::io::Write;
use std::{env, fs};

fn main() {
    built::write_built_file()
        .unwrap_or_else(|e| panic!("Failed to acquire build-time information: {:?}", e));

    let outdir = env::var("OUT_DIR").unwrap();
    let outfile 
    
fn main() {
    built::write_built_file()
        .unwrap_or_else(|e| panic!("Failed to acquire build-time information: {:?}", e));

    let outdir = env::var("OUT_DIR").unwrap();
    let outfile = format!("{}/compiled_at.txt", outdir);

    let mut fh = fs::File::create(outfile).expect("Failed to create compiled_at.txt");
    write!(fh, r#""{}""#, chrono::Local::now()).ok();
}