#13067: Abstract closed type families don't work with Backpack -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.1 (Type checker) | Keywords: backpack | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This should typecheck: {{{ {-# LANGUAGE TypeFamilies #-} unit p where module A where type family ClosedFam a where ClosedFam a = Int unit sig where signature A where type family ClosedFam a where .. unit main where dependency sig[A=p:A] }}} but instead we confusingly report: {{{ foo.bkp:9:9: error: Type constructor ‘ClosedFam’ has conflicting definitions in the module and its hsig file Main module: type family ClosedFam a :: * Hsig file: type family ClosedFam a :: * }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13067 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler