[Haskell-cafe] trace function

[Alexander Vodomerov]

  Hello!

The function trace is supposed to write debug messages to console.
However, when I trying to run the following program

import Debug.Trace

main = do
  putStrLn "xxx"
  return (trace "yyy" ())
  putStrLn "zzz"

only xxx and zzz is displayed. yyy is missing.
Why trace is not working?

PS. GHC-6.4.2, Debian Linux on x86.

With best regards,
   Alexander.