I encountered the following bug:ghc-6.4: panic! (the `impossible' happened, GHC version6.4): mkWWcpr: not a product SPIRziSPIR.SPIR{tc r3jI}Please report it as a compiler bug toglasgow-haskell-bugs@haskell.org,or http://sourceforge.net/projects/ghc/.This was in conjunction with the use of .hs-boot filesfor recursive modules, though I don't know for sure if thatactually caused the problem.Unfortunate I can't provide a simple reproducible test caseat this point, but I thought I'd let you know about thebug anyway.Fergus Henderson <fjh-mailbox-30@galois.com>