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/LibAFL/libafl
    
    the code of the file until where you have to start completion: use std::error::Error;

#[rustversion::nig
    
fn main() -> Result<(), Box<dyn Error>> {
    println!("cargo:rerun-if-changed=build.rs");
    assert!(
        cfg!(all(not(docrs), not(feature = "nautilus"))),
        "The 'nautilus' feature of libafl requires a nightly compiler"
    );
    Ok(())
}