Impossible happened while compiling the lunabot

[Don Stewart]

kyagrd:
> kyagrd at kyavaio:~/tmp/lunabot$ which ghc
> /usr/bin/ghc
> kyagrd at kyavaio:~/tmp/lunabot$ uname -a
> Linux kyavaio 2.6.29-2-686 #1 SMP Sun May 17 17:56:29 UTC 2009 i686
> GNU/Linux
> kyagrd at kyavaio:~/tmp$ ghc --version
> The Glorious Glasgow Haskell Compilation System, version 6.10.4
> kyagrd at kyavaio:~/tmp$ darcs get http://moonpatio.com/repos/lunabot
> kyagrd at kyavaio:~/tmp$ cd lunabot
> kyagrd at kyavaio:~/tmp/lunabot$ cabal install haskell-src-meta vacuum
> ...
> kyagrd at kyavaio:~/tmp/lunabot$ cabal build
> Preprocessing library lunabot-0.9.9...
> Building lunabot-0.9.9...
> [3 of 5] Compiling Luna.Bot.Eval.PackageConf (
> Luna/Bot/Eval/PackageConf.hs, dist/build/Luna/Bot/Eval/PackageConf.o )
> ghc: panic! (the 'impossible' happened)
>   (GHC version 6.10.4 for i386-unknown-linux):
> 	No match in record selector Var.tcTyVarDetails
> 
> Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Please file a bug here:

    http://hackage.haskell.org/trac/ghc/newticket?type=bug