运行 pytest with QT 时出现致命的 Python 错误

Question

我刚接触pytest, 试图运行一个测试文件却出现了问题。 我遇到了以下输出：

================================================== test session starts ==================================================
platform linux -- Python 3.7.6, pytest-5.3.5, py-1.8.1, pluggy-0.13.1 -- /home/jarel/anaconda3/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/home/jarel/workspace/spyder/rpgland/.hypothesis/examples')
PyQt5 5.9.2 -- Qt runtime 5.9.7 -- Qt compiled 5.9.6
rootdir: /home/jarel/workspace/spyder/rpgland
plugins: astropy-header-0.1.2, cov-2.8.1, openfiles-0.4.0, arraydiff-0.3, hypothesis-5.5.4, qt-3.3.0, doctestplus-0.5.0, remotedata-0.3.2
collected 1 item                                                                                                        

rpgland/test_character_window.py::test_init_character Fatal Python error: Aborted

Current thread 0x00007fb5b7229740 (most recent call first):
  File "/home/jarel/workspace/spyder/rpgland/rpgland/view/character_info_window.py", line 9 in __init__
  File "/home/jarel/workspace/spyder/rpgland/rpgland/test_character_window.py", line 20 in gui
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 788 in call_fixture_func
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 958 in pytest_fixture_setup
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 909 in execute
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 580 in _compute_fixture_value
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 499 in _get_active_fixturedef
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 483 in getfixturevalue
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 473 in _fillfixtures
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/fixtures.py", line 294 in fillfixtures
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/python.py", line 1449 in setup
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 370 in prepare
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 122 in pytest_runtest_setup
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 210 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 237 in from_call
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 210 in call_runtest_hook
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 185 in call_and_report
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 93 in runtestprotocol
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/runner.py", line 84 in pytest_runtest_protocol
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/main.py", line 271 in pytest_runtestloop
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/main.py", line 247 in _main
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/main.py", line 197 in wrap_session
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/main.py", line 240 in pytest_cmdline_main
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/home/jarel/anaconda3/lib/python3.7/site-packages/_pytest/config/__init__.py", line 93 in main
  File "/home/jarel/anaconda3/bin/pytest", line 11 in <module>
Aborted (core dumped)

它似乎卡在CharacterInfowWindow类（QtWidgets.QMainWindow的子类）中的__init __（）函数中对“super”的调用上。 此类位于character_info_window模块中。 有关问题可能是什么的任何想法吗？

- Jarel Perullo

---

请提供一个最小可重现示例 [MRE] - eyllanesc

xref https://stackoverflow.com/questions/64959516/why-a-fatal-python-error-when-testing-using-pytest-qt - Mike C

Answer 1

我今天也遇到了这个问题。对我来说，解决方案是在我的测试目录中创建一个 pytest.ini 文件，并在其中包含以下内容。

[pytest]
qt_api=pyqt5

从 https://github.com/pytest-dev/pytest-qt

如果想强制使用特定的API，请在您的pytest.ini文件中设置配置变量qt_api为pyqt5或pyside2。

一旦我在pytest.ini中设置了qt_api，测试就可以无问题运行。

- RillonDodgers

Answer 2

我理解这个输出，我最近自己也遇到了同样的问题。

问题是在创建想要测试的小部件/窗口之前，我忘记了创建QApplication。

因此，解决问题的一种方法是：

def test_something():
    test_app = QtWidgets.QApplication(sys.argv)  # <-----
    main_win = some_application.main_window.MainWindow()
    [...]

---

或者您可以使用 pytest fixture 来处理设置/拆卸。

pytest-qt 包含 qtbot fixture。从项目自述文件中得知：

主要用途是使用 qtbot fixture，负责根据需要处理 qApp 的创建 [...]

因此，在这种情况下，只需要这样做：

def test_something(qtbot):  # <-----
    main_win = some_application.main_window.MainWindow()
    [...]

- sunyata

Answer 3

在我的情况下，我遇到了“致命的Python错误：中止”的消息，但后来发现是由于我的环境引起的。

我在GitHub Codespaces中运行测试套件时看到了失败，但当我进行额外步骤进行克隆时，测试套件在Chromebook上的Crostini下工作。一旦我意识到它在我定义了“DISPLAY”变量的地方工作，我意识到Qt测试可能需要一个“DISPLAY”，无论是“xvfb”还是“真实”的显示器，所以我安装了“xvfb”，然后使用“xvfb-run pytest -v”，并成功查看了测试套件。

- dragon788