Background: I'm working on porting GHC to IA64. I have the initial unregisterised port mostly working, except for a weird problem related to this innocent bit of code (ghc/compiler/main/CmdLineOpts.hs): opt_HiVersion = read (cProjectVersionInt ++ cProjectPatchLevel) :: Int where: cProjectVersionInt = "503" cProjectPatchLevel = "0" I get... ghc-5.03: panic! (the `impossible' happened, GHC version 5.03): Prelude.read: no parse Possibly of relevance is that cProjectVersionInt is built using unpackCStringList#, whereas cProjectPatchLevel was generated statically. Below I've included an ASCII art depiction of the closure that is passed to read, after evaluation (i.e. I breakpointed after the parse error). It looks feasibly correct to me, although I may be missing something. Does anyone have any hints on where to proceed from here? Matt CmdLineOpts_lvl42_closure IND_STATIC(0x504af380) | IND(0x504af418) | CONSTR(GHC.Base_C_con_info(tag=1), 0x504af3d8, 0x504af400) | | CONSTR(GHC.Base_C#_con_info(tag=0), 0x35#) | _____________________| | IND(0x504b0018) | CONSTR(GHC.Base_C_con_info(tag=1), 0x504affc8, 0x504b0000) | | CONSTR(GHC.Base_C#_con_info(tag=0), 0x30#) | _____________________| | IND(0x504b09f0) | CONSTR(GHC.Base_C_con_info(tag=1), 0x504b09b0, 0x504b09d8) | | CONSTR(GHC.Base_C#_con_info(tag=0), 0x33#) | _____________________| | IND(Config_cProjectPatchLevel_closure) | CONSTR(GHC.Base_C_static_info(tag=1), Config_a_closure, GHC.Base_[]_closure) | | CONSTR(GHC.Base_C#_static_info(tag=0), 0x30#) | __________________________| | CONSTR(GHC.Base_[]_static_info(tag=0))