#13233: typePrimRep panic while compiling GHC with profiling -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Ahhh, I see what is happening here. `CoreArity.mkEtaWW` is refusing to eta expand the value-level arguments of `(#,#)` as they are levity polymorphic, {{{#!hs | otherwise -- We have an expression of arity > 0, -- but its type isn't a function, or a binder -- is levity-polymorphic = WARN( True, (ppr orig_n <+> ppr orig_ty) $$ ppr orig_expr ) (getTCvInScope subst, reverse eis) }}} Had I been compiling with `DEBUG` this would have been plainly obvious but I was lazily merely building with `BuildFlavour=prof`. Serves me right, I suppose. Anyways, this is a little hairy. Indeed eta expanding here would be quite suspicious. Really, it seems like we never should have produced the lambda being scrutinised in comment:7 at all given that it is levity polymorphic. I'll have to look into where this is coming from. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13233#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler