message: Minor improvement to neqo-crypto build script
  If the NSS_DIR environment variable is absolute the user may be
  presented with confusing error messages later in the build
  script.
diff: @@ -91,7 +91,12 @@ fn setup_clang() {
  fn nss_dir() -> PathBuf {
  let dir = if let Ok(dir) = env::var("NSS_DIR") {
  - PathBuf::from(dir.trim())
  + let path = PathBuf::from(dir.trim());
  + if path.is_relative() {
  + panic!("The NSS_DIR environment variable is expected to be an absolute path.");
  + }
  +
  + path
  } else {
  let out_dir = env::var("OUT_DIR").unwrap();
  let dir = Path::new(&out_dir).join("nss");
  