#14154: Some cocktail of features causes GHC panic -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
Could we fix one case this with a well-placed zonk?
I suppose we could always zonk before calling `typeKind`. But I am deeply averse to doing this. * The constraint solver does zonking on the fly, as part of canonicalisation. That is simple and nice. I don't think we should ''ever'' call zonking when we are solving constraints. * I think the constraint solver indeed obeys the invariant that we never constructor an ill-kinded type, provided you ''don't'' zonk it! But, as remarked above, `tcDataConPat` does form an ill-kinded type. I think right solution is not do to so, which isn't difficult. What I'm upset about is that it's hard to be sure when we have nailed every case. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14154#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler