#8682: GHC compilation bug ----------------------------------+--------------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.4.1 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------------- Description: Attempted to compile a relatively small & simple Haskell program. GHC crashes unpon compilation. Source code in its entirety: import System.Environment data NestedList a = Elem a | List [NestedList a] deriving (read) main = do args <- getArgs print . flatten . read $ concat args flatten :: NestedList a -> [a] flatten Elem x = [x] flatten List x = concatMap flatten x Console Log in it's entirety: user@computer:~/path/to/file/$ ghc -v file.hs Glasgow Haskell Compiler, Version 7.4.1, stage 2 booted by GHC version 7.4.1 Using binary package database: /usr/lib/ghc/package.conf.d/package.cache Using binary package database: /home/user/.ghc/x86_64-linux-7.4.1/package.conf.d/package.cache wired-in package ghc-prim mapped to ghc- prim-0.2.0.0-c2ff696e5b8ec4d4b2bc2e42085fe471 wired-in package integer-gmp mapped to integer- gmp-0.4.0.0-3cccac07aef8e27023f605c1f45bdf74 wired-in package base mapped to base-4.5.0.0-40b99d05fae6a4eea95ea69e6e0c9702 wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.7.0.0-8c8cd20e21666657195efabced685fe1 wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: -static *** Chasing dependencies: Chasing modules from: *prob07.hs Stable obj: [] Stable BCO: [] Ready for upsweep [NONREC ModSummary { ms_hs_date = Sun Jan 19 10:47:44 CST 2014 ms_mod = main:Main, ms_textual_imps = [import (implicit) Prelude, import System.Environment] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file prob07.hs Created temporary directory: /tmp/ghc6732_0 *** Checking old interface for main:Main: [1 of 1] Compiling Main ( prob07.hs, prob07.o ) *** Parser: *** Renamer/typechecker: *** Deleting temp files: Deleting: /tmp/ghc6732_0/ghc6732_0.s Warning: deleting non-existent /tmp/ghc6732_0/ghc6732_0.s *** Deleting temp dirs: Deleting: /tmp/ghc6732_0 ghc: panic! (the 'impossible' happened) (GHC version 7.4.1 for x86_64-unknown-linux): nameModule read{tv aaf} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8682 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler