ghc panic when attempting to compile DPH code
the function "tmpfn" in the attached code causes ghc to panic (the 'impossible' happened). This bug is present in ghc 6.12.1 and 6.13.20100226
ghc: panic! (the 'impossible' happened)
(GHC version 6.12.1 for i386-apple-darwin):
VectMonad.lookupFamInst: not found:
dph-seq:Data.Array.Parallel.Lifted.PArray.PData{tc rq5}
(dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
ghc-prim:GHC.Types.Double{(w) tc 3u},
dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
ghc-prim:GHC.Types.Double{(w) tc 3u},
dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
(dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
(ghc-prim:GHC.Types.Int{(w) tc 3J},
ghc-prim:GHC.Types.Double{(w) tc 3u})),
dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
ghc-prim:GHC.Types.Double{(w) tc 3u},
dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
(dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
(ghc-prim:GHC.Types.Int{(w) tc 3J},
ghc-prim:GHC.Types.Double{(w) tc 3u})),
dph-seq:Data.Array.Parallel.Lifted.PArray.PArray{tc r35}
ghc-prim:GHC.Types.Double{(w) tc 3u})