dioxus-mirror/packages/cli-config/build.rs

// warn if the "read-config" feature is enabled, but the DIOXUS_CONFIG environment variable is not set
// This means that some library is trying to access the crate's configuration, but the dioxus CLI was not used to build the application.

fn main() {
    built::write_built_file().expect("Failed to acquire build-time information");

    println!("cargo:rerun-if-env-changed=DIOXUS_CONFIG");
    let dioxus_config = std::env::var("DIOXUS_CONFIG");
    let built_with_dioxus = dioxus_config.is_ok();
    if cfg!(feature = "read-config") && !built_with_dioxus {
        println!("cargo:warning=A library is trying to access the crate's configuration, but the dioxus CLI was not used to build the application. Information about the Dioxus CLI is available at https://dioxuslabs.com/learn/0.5/CLI/installation");
    }
}