Error "pytest-cov not installed" when running "Run Tests with Coverage" in the vscode interface

[willianchan]

Type: Bug

Behaviour

When clicking the "Run Tests with Coverage" button, it shows: ERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required.

Expected Behavior is running all the tests and sending code coverage file to the folder

Steps to reproduce:

The code can be cloned here: https://github.com/willianchan/pythontddalura

I am using:

• python 3.13.2 with venv, requirements in the repo
• vscode 1.97.0
• Python Extension 2025.0.0

Diagnostic data

When clicking the "Run Tests with Coverage" button, it shows in the TEST RESULTS tab:

Running pytest with args: ['-p', 'vscode_pytest', '-v', '--rootdir=c:\\Users\\Chan\\Desktop\\Estudos\\TDD\\projeto-bytebank', '--cov=.', 'c:\\Users\\Chan\\Desktop\\Estudos\\TDD\\projeto-bytebank\\tests\\bytebank_test.py::TestClass::test_quando_idade_recebe_13_03_2000_deve_retornar_22', 'c:\\Users\\Chan\\Desktop\\Estudos\\TDD\\projeto-bytebank\\tests\\bytebank_test.py::TestClass::test_quando_sobrenome_recebe_nome_completo_deve_retornar_sobrenome']
Error[vscode-pytest]: unable to read testIds from temp file
 
ERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required. 

Traceback (most recent call last):
  File "c:\Users\Chan\.vscode\extensions\ms-python.python-2025.0.0-win32-x64\python_files\vscode_pytest\run_pytest_script.py", line 64, in <module>
    pytest.main(arg_array)
    ~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 156, in main
    config = _prepareconfig(args, plugins)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 341, in _prepareconfig
    config = pluginmanager.hook.pytest_cmdline_parse(
        pluginmanager=pluginmanager, args=args
    )
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_hooks.py", line 513, in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_manager.py", line 120, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 139, in _multicall
    raise exception.with_traceback(exception.__traceback__)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\helpconfig.py", line 105, in pytest_cmdline_parse
    config = yield
             ^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 103, in _multicall
    res = hook_impl.function(*args)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1140, in pytest_cmdline_parse
    self.parse(args)
    ~~~~~~~~~~^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1494, in parse
    self._preparse(args, addopts=addopts)
    ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1398, in _preparse
    self.hook.pytest_load_initial_conftests(
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        early_config=self, args=args, parser=self._parser
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_hooks.py", line 513, in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_manager.py", line 120, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 139, in _multicall
    raise exception.with_traceback(exception.__traceback__)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\warnings.py", line 151, in pytest_load_initial_conftests
    return (yield)
            ^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\capture.py", line 154, in pytest_load_initial_conftests
    yield
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 103, in _multicall
    res = hook_impl.function(*args)
  File "c:\Users\Chan\.vscode\extensions\ms-python.python-2025.0.0-win32-x64\python_files\vscode_pytest\__init__.py", line 70, in pytest_load_initial_conftests
    raise VSCodePytestError(
        "\n \nERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required. \n"
    )
vscode_pytest.VSCodePytestError: 
 
ERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required. 


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\Users\Chan\.vscode\extensions\ms-python.python-2025.0.0-win32-x64\python_files\vscode_pytest\run_pytest_script.py", line 67, in <module>
    run_pytest(args)
    ~~~~~~~~~~^^^^^^
  File "c:\Users\Chan\.vscode\extensions\ms-python.python-2025.0.0-win32-x64\python_files\vscode_pytest\run_pytest_script.py", line 23, in run_pytest
    pytest.main(arg_array)
    ~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 156, in main
    config = _prepareconfig(args, plugins)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 341, in _prepareconfig
    config = pluginmanager.hook.pytest_cmdline_parse(
        pluginmanager=pluginmanager, args=args
    )
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_hooks.py", line 513, in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_manager.py", line 120, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 139, in _multicall
    raise exception.with_traceback(exception.__traceback__)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\helpconfig.py", line 105, in pytest_cmdline_parse
    config = yield
             ^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 103, in _multicall
    res = hook_impl.function(*args)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1140, in pytest_cmdline_parse
    self.parse(args)
    ~~~~~~~~~~^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1494, in parse
    self._preparse(args, addopts=addopts)
    ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\config\__init__.py", line 1398, in _preparse
    self.hook.pytest_load_initial_conftests(
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        early_config=self, args=args, parser=self._parser
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_hooks.py", line 513, in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
           ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_manager.py", line 120, in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 139, in _multicall
    raise exception.with_traceback(exception.__traceback__)
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\warnings.py", line 151, in pytest_load_initial_conftests
    return (yield)
            ^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 122, in _multicall
    teardown.throw(exception)  # type: ignore[union-attr]
    ~~~~~~~~~~~~~~^^^^^^^^^^^
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\_pytest\capture.py", line 154, in pytest_load_initial_conftests
    yield
  File "c:\Users\Chan\Desktop\Estudos\TDD\projeto-bytebank\venvtdd\Lib\site-packages\pluggy\_callers.py", line 103, in _multicall
    res = hook_impl.function(*args)
  File "c:\Users\Chan\.vscode\extensions\ms-python.python-2025.0.0-win32-x64\python_files\vscode_pytest\__init__.py", line 70, in pytest_load_initial_conftests
    raise VSCodePytestError(
        "\n \nERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required. \n"
    )
vscode_pytest.VSCodePytestError: 
 
ERROR: pytest-cov is not installed, please install this before running pytest with coverage as pytest-cov is required. 

Finished running tests!

Extension version: 2025.0.0
VS Code version: Code 1.97.0 (33fc5a94a3f99ebe7087e8fe79fbe1d37a251016, 2025-02-04T22:41:26.688Z)
OS version: Windows_NT x64 10.0.19045
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.13.2
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Venv
• Value of the python.languageServer setting: Default

User Settings

languageServer: "Pylance"

testing
• pytestArgs: "<placeholder>"
• pytestEnabled: true

Installed Extensions

Extension Name	Extension Id	Version
autodocstring	njp	0.6.1
ccs-flutter-color	cir	2.0.0
copilot	Git	1.266.0
copilot-chat	Git	0.24.0
dart-code	Dar	3.104.0
debugpy	ms-	2025.0.0
flutter	Dar	3.104.0
js-debug	ms-	1.97.0
js-debug-companion	ms-	1.1.3
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material-icon-theme	PKi	5.19.0
python	ms-	2025.0.0
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vscode-coverage-gutters	rya	2.13.0
vscode-js-profile-table	ms-	1.0.10
vscode-pylance	ms-	2025.2.1
vscode-yaml	red	1.16.0

System Info

Item	Value
CPUs	12th Gen Intel(R) Core(TM) i5-12600K (16 x 3686)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	15.78GB (7.60GB free)
Process Argv	--crash-reporter-id 69f00565-e9b8-40a0-b501-e0f8ffb93f04
Screen Reader	no
VM	0%

A/B Experiments

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nativeloc2:31192216
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[eleanorjboyd]

to run coverage you will need to install pytest coverage package. You can do so from your terminal, python -m pip install pytest-cov

[willianchan]

It is already installed, the problem is that when running from this button, vscode doesn't recognize the lib:

even if i am using the same venv in vscode:

[willianchan]

Solved it, for some reason the libraries installed via terminal were not being installed in the venv in the project folder, but when running pip freeze it was showing the lib pytest-cov. I deleted the virtual env and created a new one and it just worked.

[eleanorjboyd]

sorry that was happening- glad you got it figured out!