id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
3165	":history throws ""Irrefutable pattern failed"" exception"	greenrd		"I am trying to use the GHCi debugger to find out why my code has a StackOverflow exception - but GHCi itself seems to be throwing an exception when I type :history:

{{{
(temp)[greenrd@localhost megaslurp]$ ghci Web.Twitter.Slurp               
GHCi, version 6.10.1: http://www.haskell.org/ghc/  :? for help            
Loading package ghc-prim ... linking ... done.                            
Loading package integer ... linking ... done.                             
Loading package base ... linking ... done.                                
[1 of 1] Compiling Web.Twitter.Slurp ( Web/Twitter/Slurp.hs, interpreted )
Loading package syb ... linking ... done.                                 
Loading package array-0.2.0.0 ... linking ... done.
Loading package packedstring-0.1.0.1 ... linking ... done.
Loading package containers-0.2.0.0 ... linking ... done.
Loading package pretty-1.0.1.0 ... linking ... done.
Loading package template-haskell ... linking ... done.
Loading package mtl-1.1.0.2 ... linking ... done.
Loading package filepath-1.1.0.1 ... linking ... done.
Loading package old-locale-1.0.0.1 ... linking ... done.
Loading package old-time-1.0.0.1 ... linking ... done.
Loading package unix-2.3.1.0 ... linking ... done.
Loading package directory-1.0.0.2 ... linking ... done.
Loading package process-1.0.1.0 ... linking ... done.
Loading package random-1.0.0.1 ... linking ... done.
Loading package derive-0.1.4 ... linking ... done.
Ok, modules loaded: Web.Twitter.Slurp.
*Web.Twitter.Slurp> :set -fbreak-on-error
*Web.Twitter.Slurp> :trace slurpRetry ""/host/twitter-groups.csv""
Loading package base-3.0.3.0 ... linking ... done.
Loading package bytestring-0.9.1.4 ... linking ... done.
Loading package parsec-2.1.0.1 ... linking ... done.
Loading package network-2.2.0.1 ... linking ... done.
Loading package utf8-string-0.3.4 ... linking ... done.
Loading package json-0.4.3 ... linking ... done.
Loading package HTTP-4000.0.5 ... linking ... done.
Loading package binary-0.5.0.1 ... linking ... done.
Loading package mime-0.3.0 ... linking ... done.
Loading package csv-0.1.1 ... linking ... done.
Loading package hs-twitter-0.2.5 ... linking ... done.
Stopped at <exception thrown>
_exception ::
  e = GHC.Exception.SomeException (GHC.Exception.:DException _
                                                             (GHC.Show.:DShow ...) ....)
                                  GHC.IOBase.StackOverflow
[<exception thrown>] *Web.Twitter.Slurp> :history
*** Exception: main/InteractiveEval.hs:(179,13)-(183,46): Irrefutable pattern failed for pattern Data.Maybe.Just decl
}}}"	bug	closed	normal	7.4.1	GHCi	6.10.2	fixed		mnislaih	Linux	x86	None/Unknown	Unknown