#11821: Internal error: not in scope during type checking, but it passed the renamer -------------------------------------+------------------------------------- Reporter: darchon | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1-rc3 Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC rejects | Test Case: valid program | polykinds/T11821 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2146 Wiki Page: | -------------------------------------+------------------------------------- Comment (by int-index): I've stumbled on this bug with a smaller example: {{{ {-# LANGUAGE TypeInType, ConstraintKinds #-} import Data.Proxy type SameKind (a :: k1) (b :: k2) = ('Proxy :: Proxy k1) ~ ('Proxy :: Proxy k2) }}} And the error message with GHC 8.0 is {{{ SameKind.hs:3:77: error: • GHC internal error: ‘k2’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [arZ :-> Type variable ‘k1’ = k1, as0 :-> Type variable ‘a’ = a, as2 :-> Type variable ‘b’ = b, rq7 :-> ATcTyCon SameKind] • In the first argument of ‘Proxy’, namely ‘k2’ In the kind ‘Proxy k2’ In the second argument of ‘~’, namely ‘(Proxy :: Proxy k2)’ }}} The bug is indeed fixed in GHC 8.0.2. I'm posting this because I believe a smaller test case would be a valuable addition to the test suite. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11821#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler