#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => patch * differential: => Phab:D2404 Comment: Nice catch! I had no idea that `RuntimeRep`-kinded type parameters were also represented as actual arguments to a constructor... in any case, your intuition that we need to drop the `RuntimeRep` args was spot on. (Hopefully, this would also fix derived `Functor` instances for datatypes that contain unboxed sums, but I'm not 100% sure on that.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler