Compiling module using Data.Time with -O fails; can't find HsTime.h

[Alistair Bayley]

If I try to compile this Main.hs:

module Main where
import Data.Time
main = getCurrentTime >>= print

with this ghc-6.6 command:

  ghc --make Main -o test -O

... I get this error:

C:\DOCUME~1\bayleya\LOCALS~1\Temp\ghc728_0\ghc728_0.hc:8:20: HsTime.h:
No such file or directory

Is this me doing something I shouldn't, or is there something wrong
with the way the library has been distributed?

Alistair