#8893: -XPolyKinds causes "*** Exception: Prelude.(!!): index too large" ---------------------------------------+----------------------------------- Reporter: ghorn | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc2 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time crash | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: ---------------------------------------+----------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"ffed708c30f2d1d4b4c5cd08d9c19aeb0bb623ec/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="ffed708c30f2d1d4b4c5cd08d9c19aeb0bb623ec" Apply the kind subst to the (kinds of the) quanitifed tyvars in deriveTyData I've elaboated Note [Unify kinds in deriving] to explain what is going on here. The change fixes Trac #8893. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8893#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler