Function watched_var_os

build.rs:12–15

(key: &str)

const PYTHONSYS_ENV_VAR: &str = "DEP_PYTHON3_PYTHON_FLAGS";

fn watched_var_os(key: &str) -> Option<OsString> {
    println!("cargo:rerun-if-env-changed={}", key);
    env::var_os(key)
}

fn main() {
    if cfg!(feature = "python27-sys")