#15881: GHC Panic: data A n (a :: n) :: a -> Type -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.3 Component: Compiler | Version: 8.6.2 Keywords: TypeInType | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# Language KindSignatures #-} {-# Language PolyKinds #-} import Data.Kind data A n (a :: n) :: a -> Type }}} causes a panic on 8.7.20181017 {{{ $ ~/code/headghc/inplace/bin/ghc-stage2 --interactive -ignore-dot-ghci 665_bug.hs GHCi, version 8.7.20181017: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( 665_bug.hs, interpreted ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.7.20181017 for x86_64-unknown-linux): ASSERT failed! Type-correct unfilled coercion hole {co_a1xR} Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/utils/Outputable.hs:1219:5 in ghc:Outputable assertPprPanic, called at compiler/typecheck/TcHsSyn.hs:1805:99 in ghc:TcHsSyn Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
}}} and an assertion failure in 8.7.20181029 {{{ $ ~/code/unmodifiedghc/inplace/bin/ghc-stage2 --interactive -ignore-dot- ghci 665_bug.hs GHCi, version 8.7.20181029: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( 665_bug.hs, interpreted ) *** Exception: ASSERT failed! file compiler/types/TyCon.hs, line 420
}}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15881 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler