I'm emailing these panics to this list rather than glasgow-haskell-bugs since they're obviously TH-related and I suspect are mostly to do with errors on my part or unimplemented features. Hope that's OK with people. Again the following panic is from CVS 20030903. Cheers, Ganesh ghc-6.1: panic! (the `impossible' happened, GHC version 6.1): addImpDecls Code is: module THTest where import Language.Haskell.THSyntax code1 = [d| foo = 1 |] code2 = [d| $(code1) bar = foo |]