#11824: GHC error in desugarer lookup -------------------------------------+------------------------------------- Reporter: darchon | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by darchon): I wanted to report a separate (but perhaps related) error. When I change Unbound/Generics/LocallyNameless.hs to {{{#!hs module Unbound.Generics.LocallyNameless where import Data.Typeable (Typeable) data Name a = Name class Alpha a where isTerm :: a -> Bool instance Alpha (Name a) where isTerm _ = False }}} and CLaSH/Core/Type.hs to {{{#!hs module CLaSH.Core.Type where import Unbound.Generics.LocallyNameless (Alpha (..),Name) import CLaSH.Core.TyCon data Type = VarTy type TyName = Name Type instance Alpha Type where isTerm Foo = False }}} I get: {{{ ~/devel/IfaceError(master *) $ ghci CLaSH/Core/Type.hs GHCi, version 8.1.20160412: http://www.haskell.org/ghc/ :? for help [1 of 4] Compiling Unbound.Generics.LocallyNameless ( Unbound/Generics/LocallyNameless.hs, interpreted ) [2 of 4] Compiling CLaSH.Core.Type[boot] ( CLaSH/Core/Type.hs-boot, interpreted ) [3 of 4] Compiling CLaSH.Core.TyCon ( CLaSH/Core/TyCon.hs, interpreted ) [4 of 4] Compiling CLaSH.Core.Type ( CLaSH/Core/Type.hs, interpreted ) CLaSH/Core/Type.hs:11:10: error: Not in scope: data constructor ‘Foo’ *** Exception: expectJust showModule CallStack (from HasCallStack): error, called at compiler/utils/Maybes.hs:47:27 in ghc:Maybes }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11824#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler