#15012: "Iface type variable out of scope" when compiling with -c -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.1 Resolution: | Keywords: deriving 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: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * keywords: => deriving Comment: I suspect that `DeriveGeneric` is to blame here. Here is what `-ddump- deriv` tells us about the derived `Rep1` associated type family instance for `Generic1`: {{{#!hs Derived type family instances: type GHC.Generics.Rep1 (Foo.TyFamily a_a2ta) = GHC.Generics.D1 ('GHC.Generics.MetaData "TyFamily" "Foo" "main" 'GHC.Types.False) (GHC.Generics.C1 ('GHC.Generics.MetaCons "TyFamily" 'GHC.Generics.PrefixI 'GHC.Types.False) (GHC.Generics.S1 ('GHC.Generics.MetaSel 'GHC.Base.Nothing 'GHC.Generics.NoSourceUnpackedness 'GHC.Generics.NoSourceStrictness 'GHC.Generics.DecidedLazy) (GHC.Generics.Rec0 GHC.Types.Int) GHC.Generics.:*: GHC.Generics.S1 ('GHC.Generics.MetaSel 'GHC.Base.Nothing 'GHC.Generics.NoSourceUnpackedness 'GHC.Generics.NoSourceStrictness 'GHC.Generics.DecidedLazy) (GHC.Generics.Rec0 (Foo.FakeOut b_a2q1)))) }}} Notice that `b_a2q1` is unbound in this definition! Perhaps we should be turning this into `Any`? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15012#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler