pytest overwrites .gitignore and README.md when run with --pdb

[cdeil]

There's an issue that was introduced in #3982 .

Running pytest -v test.py --pdb on a test that raises an exception will create or overwrite the .gitignore and README.md files in the current working directory.

At least I had one case where this happened, with Python 2.7.15, pytest-3.10.1, py-1.7.0, pluggy-0.8.0 because for some reason there:

cachedir: .

See https://gist.github.com/cdeil/a90f0b5727a6187d06ecbf6be68af0ad

This writing of .gitignore and README.md was introduced in #4390, so cc @nicoddemus .

Can you reproduce the issue?

[blueyed]

The README.md should not be overwritten (but gets created), but .gitignore might be overwritten even:
https://github.com/blueyed/pytest/blob/ce0ed9cd22f40d9753efeb59e62c9bb2335877cb/src/_pytest/cacheprovider.py#L123-L131

I think this should only get done if the cache dir is created?!

[cdeil]

@blueyed - Indeed, README.md wasn't overwritten.

In my project there is only a README.rst. So pytest created a new README.md file.

[blueyed]

See #4394 - however cache_dir = . is not really a good setting in general AFAICT (except for finding corner cases.. ;))

[cdeil]

@blueyed - I don't understand why cache_dir = . is chosen by pytest in this environment.

$ pytest -v gammapy/spectrum/tests/test_utils.py

Gammapy test data availability:
gammapy-extra ... yes
Gammapy environment variables:
GAMMAPY_EXTRA = /Users/deil/work/code/gammapy-extra
Setting matplotlib backend to "agg" for the tests.
=================================================================================== test session starts ===================================================================================
platform darwin -- Python 2.7.15, pytest-3.10.1, py-1.7.0, pluggy-0.8.0 -- /Users/deil/software/anaconda3/envs/gammapy-dev-py2/bin/python
cachedir: .

I can't reproduce the issue in a new folder with a single file so far.
Is there a command that I can run that gives info how cache_dir is chosen, why it's set to . in that env?
Or maybe you could try to clone https://github.com/gammapy/gammapy and see if you also get cache_dir: . with Python 2?

[blueyed]

Ah, I've thought you configured it explicitly.
Check what inifile is set to (from the header).
Are you using tox by chance?

[blueyed]

I get .pytest_cache:

platform linux2 -- Python 2.7.15, pytest-4.0.0, py-1.7.0, pluggy-0.8.0 -- /tmp/gammapy/venv2/bin/python
cachedir: .pytest_cache
rootdir: /tmp/gammapy, inifile: setup.cfg
collecting ... 
Gammapy test data availability:
gammapy-extra ... no
Gammapy environment variables:
GAMMAPY_EXTRA = not set
collected 0 items / 1 errors                                                                

Also with pytest-3.10.1, and when tests are run actually.

[blueyed]

Check the code around here:

pytest/src/_pytest/cacheprovider.py

Lines 279 to 282 in 9dec146

	cache_dir_default = ".pytest_cache"
	if "TOX_ENV_DIR" in os.environ:
	cache_dir_default = os.path.join(os.environ["TOX_ENV_DIR"], cache_dir_default)
	parser.addini("cache_dir", default=cache_dir_default, help="cache directory path.")