chore: checkpoint before Python removal

vendor/prettyplease/build.rs

@@ -0,0 +1,21 @@
+use std::env;
+use std::ffi::OsString;
+use std::process;
+
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
+    println!("cargo:rustc-check-cfg=cfg(exhaustive)");
+    println!("cargo:rustc-check-cfg=cfg(prettyplease_debug)");
+    println!("cargo:rustc-check-cfg=cfg(prettyplease_debug_indent)");
+
+    let pkg_version = cargo_env_var("CARGO_PKG_VERSION");
+    println!("cargo:VERSION={}", pkg_version.to_str().unwrap());
+}
+
+fn cargo_env_var(key: &str) -> OsString {
+    env::var_os(key).unwrap_or_else(|| {
+        eprintln!("Environment variable ${key} is not set during execution of build script");
+        process::exit(1);
+    })
+}