panic on runhaskell Setup configure on base

C:\Documents\Uni\contrib\base>darcs pull
Pulling from "http://darcs.haskell.org/packages/base"...
No remote changes to pull in!

C:\Documents\Uni\contrib\base>runhaskell Setup configure

<interactive>:1:22:
    attempting to use module `System.IO' (System/IO.hs) which is not loaded

<interactive>:1:22: Not in scope: `System.IO.stderr'

<interactive>:1:22: Not in scope: `System.IO.stdin'
ghc.exe: panic! (the 'impossible' happened)
  (GHC version 6.8.1 for i386-unknown-mingw32):
        interactiveUI:setBuffering

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Not sure what this should do, but it shouldn't panic.

Trac metadata

Trac field	Value
Version	6.8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture	Unknown