#15639: Surprising failure combining QuantifiedConstraints with Coercible -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.5 checker) | Keywords: Resolution: | QuantifiedConstraints 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: | -------------------------------------+------------------------------------- Comment (by simonpj): Can you explain more about this example? I think that it is important that * You give a role signature for `Yeah`. (What is the inferred signature?) * You export the type constructor for `Yeah` but not the data constructor. But I'm a bit lost about what you expect to happen. Can you amplify? Why do you think it should typecheck? It'd probably help to give the declaration for `Coercion` too, for those of us who do not use it daily. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15639#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler