PyQt4 crashed on exit

Question

The window will show, but crashed on exit. The coredump shows that some error happened in QtGui4.dll.

My environment is PyQt4.10.4(Qt4.8.5) 32bit version, Windows 7(64bit). Have any clue or any suggestion to find out what happened? Thanks very much.

Remove one or more controls then the crash will not happen. So weird...

settings_window.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>SettingWindow</class>
 <widget class="QWidget" name="SettingWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>465</width>
    <height>439</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Form</string>
  </property>
  <widget class="QPushButton" name="pushButton">
   <property name="geometry">
    <rect>
     <x>50</x>
     <y>350</y>
     <width>75</width>
     <height>23</height>
    </rect>
   </property>
   <property name="text">
    <string>Save</string>
   </property>
  </widget>
  <widget class="QPushButton" name="pushButton_2">
   <property name="geometry">
    <rect>
     <x>180</x>
     <y>350</y>
     <width>75</width>
     <height>23</height>
    </rect>
   </property>
   <property name="text">
    <string>Cancel</string>
   </property>
  </widget>
  <widget class="QLabel" name="label_8">
   <property name="geometry">
    <rect>
     <x>40</x>
     <y>170</y>
     <width>54</width>
     <height>12</height>
    </rect>
   </property>
   <property name="text">
    <string>label</string>
   </property>
  </widget>
  <widget class="QLineEdit" name="lineEdit_3">
   <property name="geometry">
    <rect>
     <x>110</x>
     <y>170</y>
     <width>113</width>
     <height>20</height>
    </rect>
   </property>
  </widget>
  <widget class="QLabel" name="label_9">
   <property name="geometry">
    <rect>
     <x>40</x>
     <y>230</y>
     <width>54</width>
     <height>12</height>
    </rect>
   </property>
   <property name="text">
    <string>TextLabel</string>
   </property>
  </widget>
  <widget class="QLineEdit" name="lineEdit_4">
   <property name="geometry">
    <rect>
     <x>120</x>
     <y>220</y>
     <width>113</width>
     <height>20</height>
    </rect>
   </property>
  </widget>
  <widget class="QCheckBox" name="checkBox_4">
   <property name="geometry">
    <rect>
     <x>140</x>
     <y>300</y>
     <width>71</width>
     <height>16</height>
    </rect>
   </property>
   <property name="text">
    <string>CheckBox</string>
   </property>
  </widget>
  <widget class="QLabel" name="label_11">
   <property name="geometry">
    <rect>
     <x>120</x>
     <y>190</y>
     <width>54</width>
     <height>12</height>
    </rect>
   </property>
   <property name="text">
    <string>TextLabel</string>
   </property>
  </widget>
  <widget class="QLabel" name="label_12">
   <property name="geometry">
    <rect>
     <x>130</x>
     <y>250</y>
     <width>54</width>
     <height>12</height>
    </rect>
   </property>
   <property name="text">
    <string>TextLabel</string>
   </property>
  </widget>
  <widget class="QWidget" name="layoutWidget">
   <property name="geometry">
    <rect>
     <x>40</x>
     <y>100</y>
     <width>56</width>
     <height>14</height>
    </rect>
   </property>
   <layout class="QFormLayout" name="formLayout_2">
    <property name="fieldGrowthPolicy">
     <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
    </property>
    <item row="0" column="0">
     <widget class="QLabel" name="label_2">
      <property name="text">
       <string>label</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QWidget" name="layoutWidget">
   <property name="geometry">
    <rect>
     <x>40</x>
     <y>20</y>
     <width>163</width>
     <height>40</height>
    </rect>
   </property>
   <layout class="QFormLayout" name="formLayout">
    <property name="fieldGrowthPolicy">
     <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
    </property>
    <item row="0" column="0">
     <widget class="QLabel" name="label">
      <property name="text">
       <string>label</string>
      </property>
     </widget>
    </item>
    <item row="0" column="1">
     <widget class="QCheckBox" name="checkBox">
      <property name="text">
       <string>checkbox</string>
      </property>
     </widget>
    </item>
    <item row="1" column="1">
     <widget class="QCheckBox" name="checkBox_2">
      <property name="text">
       <string>checkbox</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

settings_window.py

#-*- coding: utf-8 -*-

import sys
from PyQt4.QtGui import qApp, QDialog, QApplication
from ui_settings_window import Ui_SettingWindow

class SettingWindow(QDialog, Ui_SettingWindow):
    def __init__(self):
        super(SettingWindow, self).__init__()
        self.setupUi(self)

if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = SettingWindow()
    window.show()
    sys.exit(app.exec_())

Answer 1

sip.setdestroyonexit(False) solved my problem. This would be an ultimate answer for crash-on-exit of pyqt. The pyqt document said:

When the Python interpreter exits PyQt4 (by default) calls the C++ destructor of all wrapped instances that it owns. This happens in a random order and can therefore cause the interpreter to crash. This behavior can be disabled by calling the sip.setdestroyonexit() function.

PyQt5 always calls sip.setdestroyonexit() automatically.

Another reference should be this post, the author of pyqt talked about sip.setdestroyonexit().