[Haskell-cafe] Problem while compiling ghc 6.8

[Magicloud]

Hi,
    I got my ghc 6.8 by `darcs get --partial 
http://darcs.haskell.org/ghc-6.8/ghc`, and after `darcs-all get`, `sh 
boot`, `configure`, without any problem, I started to make it.
    Well, when compiling libraries/stm, it reports 
"Control/Concurrent/STM/TVar.hs:22:8: Not in scope: `readTVarIO'.

    I tried to reget the source without '--partial', still the same.