Testing tool does not find globally installed pytest, but VSCode terminal does.

[ghost]

Environment data

• VS Code version: 1.60.0
• OS and version: Windows 10
• Python version (& distribution if applicable, e.g. Anaconda): 3.9
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): venv
• Relevant/affected Python packages and their versions: pytest
• Value of the python.languageServer setting: Default

Expected behaviour

pytest is installed globally, not in the .venv of the project, and its path is added to python.testing.pytestPath.
When calling pytest in a VSCode terminal, with .venv activated, the tests run correctly.

Using the Testing menu should call pytest from the path entered in python.testing.pytestPath and return a similar result to what I obtain from terminal.

Actual behaviour

The Testing tool says Error discovering pytest tests (see Output > Python).
Output shows:

Error 2021-09-08 17:22:58: Error discovering pytest tests:
 [r [Error]: Traceback (most recent call last):
  File "c:\Users\xxx\.vscode\extensions\ms-python.python-2021.9.1191016588\pythonFiles\testing_tools\run_adapter.py", line 17, in <module>
    from testing_tools.adapter.__main__ import parse_args, main
  File "c:\Users\xxx\.vscode\extensions\ms-python.python-2021.9.1191016588\pythonFiles\testing_tools\adapter\__main__.py", line 9, in <module>
    from . import pytest, report
  File "c:\Users\xxx\.vscode\extensions\ms-python.python-2021.9.1191016588\pythonFiles\testing_tools\adapter\pytest\__init__.py", line 7, in <module>
    from ._discovery import discover
  File "c:\Users\xxx\.vscode\extensions\ms-python.python-2021.9.1191016588\pythonFiles\testing_tools\adapter\pytest\_discovery.py", line 8, in <module>
    import pytest
ModuleNotFoundError: No module named 'pytest'

	at ChildProcess.<anonymous> (c:\Users\xxx\.vscode\extensions\ms-python.python-2021.9.1191016588\out\client\extension.js:9:380706)
	at Object.onceWrapper (events.js:422:26)
	at ChildProcess.emit (events.js:315:20)
	at maybeClose (internal/child_process.js:1048:16)
	at Process.ChildProcess._handle.onexit (internal/child_process.js:288:5)]

[rlittlefield]

I'm seeing something similar. I reverted my extension to 2021.6.944021595 and it seems to respect my pytestPath and pytestArgs again.

[ghost]

For information, it does work properly if I install pytest in the virtual env.

[karthiknadig]

Looks like pytestPath was only honored when running tests. But not always when discovering tests, it may work sometimes but that was not by design. We are currently working on re-writing the test adapter, and we will handle these scenarios there.

Closing in favor of #17242