message: Handle PTY EIO error for Rust 1.55+
  `ErrorKind::Other` no longer includes `EIO` since Rust 1.55:
  It was not precise enough from the very beginning, as the comment says
  that only EIO should be hidden, while the code was any uncategorised
  errors.
diff: @@ -394,7 +394,7 @@ where
  // This sucks, but checking the process is either racy or
  // blocking.
  #[cfg(target_os = "linux")]
  - if err.kind() == ErrorKind::Other {
  + if err.raw_os_error() == Some(libc::EIO) {
  continue;
  }
  