问Qshow分割故障

EN

  setText mb $ "Hello World"
  qshow mb () -- Segmentation Failt 
  --print ("Hello world") -- it works

module Main where

import Qtc.Classes.Qccs
import Qtc.Classes.Gui
import Qtc.ClassTypes.Gui
import Qtc.Core.Base
import Qtc.Gui.Base
import Qtc.Gui.QApplication
import Qtc.Gui.QWidget
import Qtc.Gui.QPushButton
import Qtc.Gui.QAbstractButton
import Qtc.Gui.QMessageBox

type MyQPushButton = QPushButtonSc (CMyQPushButton)
data CMyQPushButton = CMyQPushButton

myQPushButton :: String -> IO (MyQPushButton)
myQPushButton b = qSubClass $ qPushButton b

main :: IO Int
main = do
  qApplication ()
  hello <- myQPushButton "Hello qtHaskell World"
  resize hello (200::Int, 60::Int)
  mb <- qMessageBox hello 
  connectSlot hello "clicked()" hello "click()" $ on_hello_clicked mb
  qshow hello ()
  qApplicationExec ()

on_hello_clicked :: QMessageBox () -> MyQPushButton -> IO ()
on_hello_clicked mb this
  = do
  tt <- text this ()
  setText mb $ "You have clicked " ++ tt
  qshow mb ()

> > ncdy@Cndy ~/Haskell $ valgrind ./a
> ==13467== Memcheck, a memory error detector
> ==13467== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
> ==13467== Using Valgrind-3.6.0 and LibVEX; rerun with -h for copyright
> info
> ==13467== Command: ./a
> ==13467== 
> 
> ==13467== Syscall param writev(vector[...]) points to
> uninitialised byte(s)
> ==13467==    at 0x40008D2: ??? (in /lib/ld-2.11.2.so)
> ==13467==  Address 0x6e85d97 is 2,703 bytes inside a block of size 16,384
> alloc'd
> ==13467==    at 0x4027834: calloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
> ==13467==    by 0x69C4BD4: XOpenDisplay (in
> /usr/lib/libX11.so.6.3.0)
> ==13467==    by 0x4C505F53: ???
> ==13467== 
> ==13467== 
> ==13467== Process terminating with default action of signal 11 (SIGSEGV)
> ==13467==  General Protection Fault
> ==13467==    at 0x5957480: ??? (in /usr/lib/qt4/libQtGui.so.4.7.1)
> ==13467==    by 0x5B5FD81: ??? (in /usr/lib/qt4/libQtGui.so.4.7.1)
> ==13467==    by 0x5B6BC19: ??? (in /usr/lib/qt4/libQtGui.so.4.7.1)
> ==13467==    by 0x5B71B3C: ??? (in /usr/lib/qt4/libQtGui.so.4.7.1)
> ==13467==    by 0x5AE757D: QPainter::drawPixmap(QRectF const&,
> QPixmap const&, QRectF const&) (in
> /usr/lib/qt4/libQtGui.so.4.7.1)
> ==13467==    by 0xA71AA68: Oxygen::Helper::renderWindowBackground(QPainter*,
> QRect const&, QWidget const*, QWidget
> const*, QColor const&, int, int) (in
> /usr/lib/liboxygenstyle.so.4.5.0)
> ==13467== Invalid free() / delete / delete[]
> ==13467==    at 0x402868B: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
> ==13467==    by 0x52F78DB: ??? (in /lib/libc-2.11.2.so)
> ==13467==    by 0x105FFFF: ???
> ==13467==  Address 0x5133a98 is not stack'd, malloc'd or (recently) free'd
> ==13467== 
> ==13467== 
> ==13467== HEAP SUMMARY:
> ==13467==     in use at exit: 1,968,209 bytes in 27,864 blocks
> ==13467==   total heap usage: 65,595 allocs, 37,732 frees, 6,175,162 bytes
> allocated
> ==13467== 
> ==13467== LEAK SUMMARY:
> ==13467==    definitely lost: 18,054 bytes in 259 blocks
> ==13467==    indirectly lost: 94,591 bytes in 628 blocks
> ==13467==      possibly lost: 489,039 bytes in 5,656 blocks
> ==13467==    still reachable: 1,366,525 bytes in 21,321 blocks
> ==13467==         suppressed: 0 bytes in 0 blocks
> ==13467== Rerun with --leak-check=full to see details of leaked memory
> ==13467== 
> ==13467== For counts of detected and suppressed errors, rerun with: -v
> ==13467== Use --track-origins=yes to see where uninitialised values come
> from
> ==13467== ERROR SUMMARY: 3 errors from 2 contexts (suppressed: 15 from 8)
> Segmentation fault

ghc --make -package qt -fglasgow-exts -O2 -o a HCK.hs -i