when I run puppet on the following code:

/tmp/require.pp¶

class x {
  notify{'a':}
}

class y {
  require x
  notify{'b':}
}

include y

I get the following:

warning: Scope(Class[Y]): The 'require' function is only compatible with clients at 0.25 and above; including class but not adding dependency
notice: b
notice: /Stage[main]/Y/Notify[b]/message: defined 'message' as 'b'
notice: a
notice: /Stage[main]/X/Notify[a]/message: defined 'message' as 'a'

The order is incorrect, and there is an invalid warning.