Pytest：Windows 致命异常：访问冲突
Posted
技术标签:
【中文标题】Pytest：Windows 致命异常：访问冲突【英文标题】：Pytest: Windows fatal exception: access violation 【发布时间】：2020-04-23 07:29:38 【问题描述】：我正在使用 pytest 为我的项目运行一些测试。有时（大约 30% 到 50%）我在测试完成后会出错。但这会阻止测试引擎创建测试报告，这真的很痛苦。
错误：
Windows fatal exception: access violation
Current thread 0x000019e0 (most recent call first):
File "C:\Python38\lib\threading.py", line 1200 in invoke_excepthook
File "C:\Python38\lib\threading.py", line 934 in _bootstrap_inner
File "C:\Python38\lib\threading.py", line 890 in _bootstrap
Thread 0x00001b0c (most recent call first):
File "C:\Python38\lib\site-packages\serial\serialwin32.py", line 240 in _close
File "C:\Python38\lib\site-packages\serial\serialwin32.py", line 246 in close
File "C:\NoBackup\svn\test_system_smets2\pyets\plugins\plugin_zigbee_dongle.py", line 141 in disconnect
File "C:\NoBackup\svn\test_system_smets2\pyets\plugins\plugin_zigbee_dongle.py", line 232 in stop
File "C:\NoBackup\svn\test_system_smets2\pyets\testengine\plugin_manager.py", line 286 in stop
File "C:\NoBackup\svn\test_system_smets2\pyets\testengine\testengine.py", line 112 in session_finalize
File "C:\NoBackup\svn\test_system_smets2\pyets\testengine\pytest_test_engine.py", line 58 in test_engine
File "C:\Python38\lib\site-packages\_pytest\fixtures.py", line 800 in _teardown_yield_fixture
File "C:\Python38\lib\site-packages\_pytest\fixtures.py", line 871 in finish
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 318 in _callfinalizers
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 328 in _teardown_with_finalization
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 310 in _pop_and_teardown
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 350 in _teardown_towards
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 342 in teardown_exact
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 148 in pytest_runtest_teardown
File "C:\Python38\lib\site-packages\pluggy\callers.py", line 187 in _multicall
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 83 in <lambda>
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 92 in _hookexec
File "C:\Python38\lib\site-packages\pluggy\hooks.py", line 286 in __call__
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 217 in <lambda>
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 244 in from_call
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 216 in call_runtest_hook
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 186 in call_and_report
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 101 in runtestprotocol
File "C:\Python38\lib\site-packages\_pytest\runner.py", line 85 in pytest_runtest_protocol
File "C:\Python38\lib\site-packages\pluggy\callers.py", line 187 in _multicall
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 83 in <lambda>
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 92 in _hookexec
File "C:\Python38\lib\site-packages\pluggy\hooks.py", line 286 in __call__
File "C:\Python38\lib\site-packages\_pytest\main.py", line 272 in pytest_runtestloop
File "C:\Python38\lib\site-packages\pluggy\callers.py", line 187 in _multicall
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 83 in <lambda>
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 92 in _hookexec
File "C:\Python38\lib\site-packages\pluggy\hooks.py", line 286 in __call__
File "C:\Python38\lib\site-packages\_pytest\main.py", line 247 in _main
File "C:\Python38\lib\site-packages\_pytest\main.py", line 191 in wrap_session
File "C:\Python38\lib\site-packages\_pytest\main.py", line 240 in pytest_cmdline_main
File "C:\Python38\lib\site-packages\pluggy\callers.py", line 187 in _multicall
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 83 in <lambda>
File "C:\Python38\lib\site-packages\pluggy\manager.py", line 92 in _hookexec
File "C:\Python38\lib\site-packages\pluggy\hooks.py", line 286 in __call__
File "C:\Python38\lib\site-packages\_pytest\config\__init__.py", line 124 in main
File "testrun.py", line 1184 in run_single_test
File "testrun.py", line 1548 in main
File "testrun.py", line 1581 in <module>
有人知道如何修复或调试它吗？
我在 win10 上使用 pytest 5.4.1 和 python 3.8.0。但这也可以在较旧的 pytest 版本中重现。
插件 plugin_zigbee_dongle.py 使用 pyserial (3.4) 与线程中的 usb-rf-dongle 通信。以下代码是这个插件的sn-p：
import serial
import threading
class ZigbeeDongleSerial(object):
def __init__(self, test_engine):
self.ser = serial.Serial()
self.test_engine = test_engine
# ----------------------------------------------------------
def connect(self,
port,
baud,
timeout):
self.ser.baudrate = baud
self.ser.timeout = timeout
self.ser.port = port
self.ser.open()
# ----------------------------------------------------------
def disconnect(self):
try:
if self.is_connected():
self.ser.close() # <------- This is line 141 ----------
except:
pass
# ----------------------------------------------------------
# ----------------------------------------------------------
class PluginZigbeeDongle(PluginBase):
# ----------------------------------------------------------
def __init__(self, test_engine):
super(PluginZigbeeDongle, self).__init__()
self.test_engine = test_engine
self.dongle_serial = ZigbeeDongleSerial(self.test_engine)
self._startup_lock = threading.Lock()
self._startup_lock.acquire()
self.reader_thread = threading.Thread(target=self._read_worker, name="ZigbeeDongleThread")
# ----------------------------------------------------------
def start(self):
super(PluginZigbeeDongle, self).start()
# connect the serial port
self.dongle_serial.connect()
# start the reader thread
if self.dongle_serial.is_connected():
self.reader_thread.start()
# ----------------------------------------------------------
def stop(self):
super(PluginZigbeeDongle, self).stop()
# disconnect the serial port
if self.dongle_serial.is_connected():
self.dongle_serial.disconnect() # <------- This is line 232 ----------
# stop the reader thread
if self.reader_thread.is_alive():
self.reader_thread.join()
# ----------------------------------------------------------
def _read_worker(self):
# start-up is now complete
self._startup_lock.release()
# handle the incoming character stream
done = False
while not done:
try:
c = self.dongle_serial.read_byte()
except serial.SerialException:
done = True
except AttributeError:
done = True
if not done:
self._read_parser(c)
【问题讨论】：
plugin_zigbee_dongle.py 中出现错误，它看起来像您项目中的模块。如果没有看到那里发生了什么，就不可能说出问题所在。你能提供一个minimal reproducible example吗？
在使用带有 cython 的夹具和底层 c 库时，我也面临访问冲突问题
@hoefling：谢谢你的评论，我加了一个代码sn-p
我在没有安装 pyserial 的情况下得到了这个。 OTOH，我已经安装了 pytest-qt，当我使用 qtbot 夹具执行操作时，似乎会出现这种错误，但只是偶尔出现：目前我不知道是哪种编码导致它。它似乎与使用 unittest.mock.patch 模拟 PyQt5 对象上的方法有关。但是其他测试处理得很好，所以现在我很困惑。
【参考方案1】：
将 pyserial 从 3.4 版降级到 2.7 版解决了这个问题
【讨论】：
以上是关于Pytest：Windows 致命异常：访问冲突的主要内容，如果未能解决你的问题，请参考以下文章
javafx 致命错误异常访问冲突（问题框架：jfxmedia.dll）
致命错误：未捕获的异常“PDOException”，带有消息“SQLSTATE [42000]：语法错误或访问冲突 PHP 和 PDO
带有消息“SQLSTATE [42000]”的未捕获异常“PDOException”：语法错误或访问冲突：
WindowsError：异常：使用从 C++ 到 Python 的 ctypes 创建 DLL 时出现访问冲突或 Windows 错误 193