use std::{env, process}; fn main() { // Prevent unnecessary rerunning of this build script println!("cargo:rerun-if-changed=build.rs"); let tls_features = [ ("tls-native", env::var_os("CARGO_FEATURE_TLS_NATIVE").is_some()), ("tls-rustls-native-roots", env::var_os("CARGO_FEATURE_TLS_RUSTLS_NATIVE_ROOTS").is_some()), ("tls-rustls-webpki-roots", env::var_os("CARGO_FEATURE_TLS_RUSTLS_WEBPKI_ROOTS").is_some()), ]; if tls_features.iter().filter(|(_, a)| *a).count() > 1 { eprintln!("error: Only one tls features can be enabled."); for (f, a) in &tls_features { eprintln!(" {f}: {}", if *a { "enabled" } else { "disabled" }); } process::exit(1); } }