#14040: Typed holes regression in GHC 8.0.2: No skolem info: z_a1sY[sk:2] -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.2 checker) | Keywords: TypeInType, Resolution: | TypeFamilies, PartialTypeSignatures Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #13877 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Interestingly, the original program no longer panics on GHC HEAD, but the program in comment:2 still panics, this time with a slightly different panic: {{{ GHCi, version 8.5.20171205: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:56:28: error:ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.5.20171205 for x86_64-unknown-linux): No skolem info: [a1_a1yY[sk:1]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable pprPanic, called at compiler/typecheck/TcErrors.hs:2892:5 in ghc:TcErrors Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Is it worth adding a regression test for the original program, or should I wait until the program in comment:2 has been fixed as well? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14040#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler