#13877: GHC panic: No skolem info: k2 -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1 checker) | 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 RyanGlScott): Going back to the original program, if you change this line: {{{#!hs listElimTyFun = listElimPoly @(:->) @a @p @l }}} To this: {{{#!hs listElimTyFun = listElimPoly @(:->) }}} You get a different panic: {{{ $ /opt/ghc/8.2.1/bin/ghci Bug.hs GHCi, version 8.2.0.20170623: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Eliminator ( Bug.hs, interpreted ) ghc: panic! (the 'impossible' happened) (GHC version 8.2.0.20170623 for x86_64-unknown-linux): piResultTy Fun [a_a5hm[sk:2]] (':->) * l_a5ho[sk:2] Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:948:35 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13877#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler