#14898: Panic with repSplitAppTys -------------------------------------+------------------------------------- Reporter: ryanreich | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I get a GHC panic while compiling a rather large module that contains a fairly simple function: {{{#!hs import Control.Monad.Reader usingReader :: (Monad m) => r -> (a -> ReaderT r m b) (a -> m b) usingReader r f = flip runReaderT r . f }}} Unfortunately, that function alone in a module does not trigger the panic. The error message is: {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.2.1 for x86_64-unknown-linux): repSplitAppTys a_ahFs[sk:1] ReaderT r_ahFr[sk:1] m_ahFq[sk:1] b_ahFt[sk:1] [] Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:808:9 in ghc:Type }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14898 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler