#9193: GHC panic usinig HList and Lens -------------------------------------------+------------------------------- Reporter: maxigit | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Architecture: x86 | Unknown/Multiple Difficulty: Easy (less than 1 hour) | Type of failure: GHCi crash Blocked By: | Test Case: Related Tickets: | Blocking: -------------------------------------------+------------------------------- This bug might have been fixed in GHC 7.8.2 but I haven't been able to test it. Some packages required to reproduce the bug are broken under 7.8.*. GHC 'panic' whilst trying to compile the following. Strangely, removing doing the last line of code 'manually' in ghci works. {{{ {-# LANGUAGE TypeFamilies, DataKinds, PolyKinds, TypeOperators #-} {-# LANGUAGE NoMonomorphismRestriction #-} module Database.Harehouse.SQLFragment where import Data.HList import Control.Lens hiding(from) x = hLens' (Label :: Label "x") }}} Note. I'm using HList-0.3.4.1 and lens-4.1.2.1. I think it wasn't working with lens 4.2 either, but since I tried to install ghc 7.8.2 I haven't be able to reinstall lens 4.2. (cabal hell). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9193 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler