#10432: panic with kind polymorphism -------------------------------------+------------------------------------- Reporter: Ashley Yakeley | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.10.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): -------------------------------------+------------------------------------- Comment (by simonpj): It does not work in HEAD for me. I get {{{ simonpj@cam-05-unx:~/tmp$ ~/5builds/HEAD-4/inplace/bin/ghc-stage1 -c -dcore-lint T10432.hs RAE1 [W] cobox_arV :: ka1_arO[sk] ~ kb1_arP[sk] (CNonCanonical) ka1_arO[sk] kb1_arP[sk] False T10432.hs:17:15: error: Couldn't match kind ‘ka1’ with ‘kb1’ ‘ka1’ is untouchable inside the constraints: 'WrapType a1 ~ 'WrapType b1 bound by the type signature for: foo :: ('WrapType a1 ~ 'WrapType b1) => r1 at T10432.hs:17:15-46ghc-stage1: panic! (the 'impossible' happened) (GHC version 7.11.20151006 for x86_64-unknown-linux): No skolem info: kb1_arP[sk] }}} for the code in comment:1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10432#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler