internal error: ARR_WORDS object entered!

I got this while playing around with vacuum-cairo:

$ ghci
ghci> :m +System.Vacuum.Cairo
ghci> :m +Data.Text
ghci> :m +Data.IntMap
ghci> view $ fromList [(1, "hi" :: Text)]
<interactive>: internal error: ARR_WORDS object entered!
    (GHC version 6.10.2 for x86_64_unknown_linux)
    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
Aborted

Trac metadata

Trac field	Value
Version	6.10.4
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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