#14121: ghc master requires -XTypeInType where 8.2.1 does not -------------------------------------+------------------------------------- Reporter: duog | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.3 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This was found while building https://hackage.haskell.org/package/foundation with ghc head. The following code is reduced from Basement.Primitive.Error: {{{ {-# LANGUAGE MagicHash, PolyKinds, RankNTypes #-} module FoundationRegression where import GHC.Prim import GHC.Types (RuntimeRep) error :: forall (r :: RuntimeRep) . forall (a :: TYPE r) . String -> a error s = raise# undefined }}} This compiles works with 8.2.1, but fails on master: {{{ $ /opt/ghc/8.2.1/bin/ghc -c FoundationRegression.hs $ /opt/ghc/head/bin/ghc -c FoundationRegression.hs FoundationRegression.hs:7:17: error: Variable ‘r’ used as both a kind and a type Did you intend to use TypeInType? | 7 | error :: forall (r :: RuntimeRep) . forall (a :: TYPE r) . String -> a | ^^^^^^^^^^^^^^^^^ }}} After adding a TypeInType language pragma the program is accepted. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14121 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler