message: Disable posix_fadvise test on macOS, not in libc
diff: extern crate libc;
  +#[cfg(not(target_os = "macos"))]
  +fn test_posix_fadvise() {
  use std::convert::TryInto;
  use std::env::temp_dir;
  use std::fs::{File, remove_file};
  use std::io::Write;
  use std::os::unix::io::AsRawFd;
  -fn main() {
  let path = temp_dir().join("miri_test_libc.txt");
  // Cleanup before test
  remove_file(&path).ok();
  @@ -34,3 +35,8 @@ fn main() {
  remove_file(&path).unwrap();
  assert_eq!(result, 0);
  }
  +
  +fn main() {
  + #[cfg(not(target_os = "macos"))]
  + test_posix_fadvise();
  +}
  