What steps will reproduce the problem?
Just trying to install git-annex last release (20121120) from cabal or from bundled sources

What is the expected output? What do you see instead?
Build stop like this :
(doing cabal install or build from the bundle)
...
[161 of 284] Compiling Assistant.Alert  ( Assistant/Alert.hs, dist/build/git-annex/git-annex-tmp/Assistant/Alert.o )
[162 of 284] Compiling Assistant.Types.DaemonStatus ( Assistant/Types/DaemonStatus.hs, dist/build/git-annex/git-annex-tmp/Assistant/Types/DaemonStatus.o )
[163 of 284] Compiling Assistant.Monad  ( Assistant/Monad.hs, dist/build/git-annex/git-annex-tmp/Assistant/Monad.o )

Assistant/Monad.hs:86:16:
    Couldn't match expected type `Assistant a'
                with actual type `Reader AssistantData a'
    Expected type: (AssistantData -> a) -> Assistant a
      Actual type: (AssistantData -> a) -> Reader AssistantData a
    In the expression: reader
    In an equation for `getAssistant': getAssistant = reader

Assistant/Monad.hs:93:15:
    Couldn't match expected type `Assistant t0'
                with actual type `Reader r0 a0'
    In the return type of a call of `reader'
    In a stmt of a 'do' block: st <- reader threadState
    In the expression:
      do { st <- reader threadState;
           liftIO $ runThreadState st a }

Assistant/Monad.hs:99:14:
    Couldn't match expected type `Assistant t0'
                with actual type `Reader r0 a0'
    In the return type of a call of `reader'
    In a stmt of a 'do' block: d <- reader id
    In the expression:
      do { d <- reader id;
           liftIO $ io $ runAssistant d a }

Assistant/Monad.hs:105:14:
    Couldn't match expected type `Assistant t0'
                with actual type `Reader r0 a0'
    In the return type of a call of `reader'
    In a stmt of a 'do' block: d <- reader id
    In the expression:
      do { d <- reader id;
           return $ runAssistant d a }

Assistant/Monad.hs:110:14:
    Couldn't match expected type `Assistant t0'
                with actual type `Reader r0 a0'
    In the return type of a call of `reader'
    In a stmt of a 'do' block: d <- reader id
    In the expression:
      do { d <- reader id;
           return $ \ v -> runAssistant d $ a v }

Assistant/Monad.hs:115:14:
    Couldn't match expected type `Assistant t0'
                with actual type `Reader r0 a0'
    In the return type of a call of `reader'
    In a stmt of a 'do' block: d <- reader id
    In the expression:
      do { d <- reader id;
           return $ \ v1 v2 -> runAssistant d (a v1 v2) }

Assistant/Monad.hs:120:12:
    Couldn't match expected type `Assistant a0'
                with actual type `Reader r0 a1'
    In the return type of a call of `reader'
    In the first argument of `(>>=)', namely `reader v'
    In the expression: reader v >>= liftIO . io




What version of git-annex are you using? On what operating system?
- version 3.20121112
- Ubuntu 12.04 LTS, 64 bits

> Dup of [[3.20121112_build_fails_on_Ubuntu_12.04]]. --[[Joey]] [[done]]
