sqlx offline preparation for nix

build.rs

use std::env::{self, VarError};

// generated by `sqlx migrate build-script`
fn main() {

    let use_db = |_url| {
        // println!("cargo:rustc-env=DATABASE_URL={}", url);
        println!("cargo:rerun-if-changed=migrations");
    };

    let use_json = || println!("cargo:rustc-env=SQLX_OFFLINE=true");

    println!("cargo:rerun-if-env-changed=DATABASE_URL");

    match env::var("DATABASE_URL") {
        Ok(url) => use_db(url),
        Err(VarError::NotPresent) => {
            println!("cargo:warning={}", "using `.sqlx` for schema");
            use_json()
        }
        Err(e) => panic!("$DATABASE_URL: {e:?}"),
    }
}