#15673: ghc: panic! (the 'impossible' happened) --------------------------------------+--------------------------------- Reporter: mcmayer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.4 Component: Compiler | Version: 8.4.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+--------------------------------- The following few lines produce a GHC panic: {{{#!hs module Main where import Data.Bits (shift) badOne :: [Int] -> Integer badOne is = sum $ zipWith (\n _->shift 1 n) (enumFrom 0) is main = return () :: IO () }}} The function is stripped down as much as possible, it doesn't perform anything all to meaningful anymore. The error message is: {{{#!bash ghc: panic! (the 'impossible' happened) (GHC version 8.4.3 for x86_64-apple-darwin): heap overflow }}} All else is off-the-shelf stack lts-12.10 via {{{#!bash stack new bad-one simple }}} Tested on Mac OS X and Debian. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15673 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler