message: Make newlib and pci mutually exclusive
diff: )]
  #![cfg_attr(target_os = "none", cfg_attr(test, no_main))]
  +#[cfg(all(feature = "newlib", feature = "pci"))]
  +compile_error!("feature \"newlib\" and feature \"pci\" cannot be enabled at the same time");
  +
  // EXTERNAL CRATES
  #[macro_use]
  extern crate alloc;
  