#9574: GHC Panic: No Skolem Info -------------------------------------+------------------------------------- Reporter: ian_mi | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: fixed | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | polykinds/T9574 | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * testcase: => polykinds/T9574 * resolution: => fixed Comment: Thank you for reducing the test case so well. The problem is that the instance {{{ instance Funct ('KProxy :: KProxy o) where type Codomain 'KProxy = NatTr (Proxy :: o -> *) }}} should bind 'o' on the LHS of the type instance: {{{ instance Funct ('KProxy :: KProxy o) where type Codomain ('KProxy :: KProxy o) = NatTr (Proxy :: o -> *) }}} Otherwise there is nothing to connect the lhs and rhs. I've added this check. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9574#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler