GHC compilation bug

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

Trac metadata

Trac field	Value
Version	7.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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