#8865: Cannot derive well-kinded instance of form ‘Category ----------------------------------------------+---------------------------- Reporter: adinapoli | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: Resolution: | 7.8.1-rc2 Operating System: MacOS X | Keywords: Type of failure: GHC rejects valid program | Architecture: x86_64 Test Case: | (amd64) Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"f521a26cb741409011137115d17232df901c3c94/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="f521a26cb741409011137115d17232df901c3c94" Unify, rather than match, in GND processing (fixes Trac #8865) Yet another small way in which polymorphic kinds needs a bit of care See Note [Unify kinds in deriving] in TcDeriv }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8865#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler