#11348: Local open type families instances ignored during type checking -------------------------------------+------------------------------------- Reporter: alexvieth | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc1 Resolution: | 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: | -------------------------------------+------------------------------------- Comment (by goldfire): Yay yay yay. Thanks! The issue here is a known infelicity, but it seemed to me that fixing it would take a fair amount of reinstallation of plumbing. I think you'll have to type-check instance declarations (the first of the two passes in !TcInstDcls) in with mutually recursive groups. A type whose kind mentions an open type family depends on the instances of that family. If you're up to this task, that would be wonderful. I'm more than happy to advise. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11348#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler