#15142: GHC HEAD regression: tcTyVarDetails -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: goldfire Type: bug | Status: new Priority: highest | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.5 checker) | Keywords: TypeInType, Resolution: | TypeFamilies, CUSKs 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): I have good news and bad news. The bad news is that this still does not typecheck on GHC HEAD. The good news is that it no longer panics! It now gives the following, lovely error message: {{{ $ /opt/ghc/head/bin/ghci Bug.hs GHCi, version 8.7.20180621: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:8:42: error: • Expected a type, but ‘k’ has kind ‘k’ • In the kind ‘[(k, Type)]’ | 8 | class ListTuple (tuple :: Type) (as :: [(k, Type)]) where | ^ }}} So that's... nice, I guess. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15142#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler