Cannot enter WarningsChecker twice

• Include a detailed description of the bug or suggestion

pytest.warns fails with RuntimeError: Cannot enter WarningsChecker(record=True) twice when parametrizing test function multiple times.

• Minimal example if possible

This works just fine:

import pytest
import warnings

@pytest.mark.parametrize("expectation", [
	pytest.warns(DeprecationWarning,
					  match="Message A"),
	pytest.warns(DeprecationWarning,
					  match="Message B"),					  
])
def test_parametrized_warnings(expectation):
    with expectation:
	    warnings.warn("Message A", DeprecationWarning)

But when parametrizing another argument independently:

import pytest
import warnings

@pytest.mark.parametrize("other", [1, 2])
@pytest.mark.parametrize("expectation", [
	pytest.warns(DeprecationWarning,
					  match="Message A"),
	pytest.warns(DeprecationWarning,
					  match="Message B"),					  
])
def test_parametrized_warnings(other, expectation):
    with expectation:
	    warnings.warn("Message A", DeprecationWarning)

Then I get this error:

RuntimeError: Cannot enter WarningsChecker(record=True) twice

• pytest and operating system versions

pytest 4.0.1 and Windows 10

• pip list of the virtual environment you are using

Package                  Version
------------------------ ----------
alabaster                0.7.12
allure-pytest            2.5.4
allure-python-commons    2.5.4
apipkg                   1.5
asn1crypto               0.24.0
asv                      0.3.1
atomicwrites             1.2.1
attrs                    18.2.0
aws-xray-sdk             0.95
Babel                    2.6.0
backcall                 0.1.0
beautifulsoup4           4.7.1
bleach                   3.0.2
blosc                    1.7.0
boto                     2.49.0
boto3                    1.9.75
botocore                 1.12.75
Bottleneck               1.2.1
certifi                  2018.11.29
cffi                     1.11.5
chardet                  3.0.4
colorama                 0.4.1
coverage                 4.5.2
cpplint                  1.3.0
cryptography             2.4.2
cycler                   0.10.0
Cython                   0.29.2
decorator                4.3.0
docker                   3.6.0
docker-pycreds           0.4.0
docutils                 0.14
ecdsa                    0.13
entrypoints              0.3
et-xmlfile               1.0.1
execnet                  1.5.0
fastparquet              0.2.1
flake8                   3.6.0
flake8-comprehensions    1.4.1
flake8-rst               0.7.0
future                   0.17.1
gitdb2                   2.0.5
GitPython                2.1.11
html5lib                 1.0.1
hypothesis               3.86.7
idna                     2.8
imagesize                1.1.0
ipykernel                5.1.0
ipython                  7.2.0
ipython-genutils         0.2.0
isort                    4.3.4
jdcal                    1.4
jedi                     0.13.2
Jinja2                   2.10
jmespath                 0.9.3
jsondiff                 1.1.1
jsonpickle               1.0
jsonschema               2.6.0
jupyter-client           5.2.4
jupyter-core             4.4.0
kiwisolver               1.0.1
llvmlite                 0.27.0
lxml                     4.3.0
MarkupSafe               1.1.0
matplotlib               3.0.2
mccabe                   0.6.1
mistune                  0.8.4
mock                     2.0.0
more-itertools           4.3.0
moto                     1.3.7
nbconvert                5.3.1
nbformat                 4.4.0
nbsphinx                 0.4.1
numba                    0.42.0
numexpr                  2.6.9
numpy                    1.15.4
numpydoc                 0.8.0
openpyxl                 2.5.12
packaging                18.0
pandas                   0.23.4
pandocfilters            1.4.2
parso                    0.3.1
pbr                      5.1.1
PeakUtils                1.3.0
pickleshare              0.7.5
pip                      10.0.1
pluggy                   0.8.0
prompt-toolkit           2.0.7
py                       1.7.0
pyaml                    18.11.0
pyarrow                  0.11.1
pycodestyle              2.4.0
pycparser                2.19
pycryptodome             3.7.2
pycryptodomex            3.7.2
pyflakes                 2.0.0
Pygments                 2.3.1
pyModbusTCP              0.1.8
pyparsing                2.3.0
pypiwin32                223
pytest                   4.0.1
pytest-cov               2.6.1
pytest-forked            0.2
pytest-runner            4.2
pytest-xdist             1.25.0
python-dateutil          2.7.5
python-jose              2.0.2
pytz                     2018.7
pywin32                  224
PyYAML                   3.13
pyzmq                    17.1.2
requests                 2.21.0
responses                0.10.5
s3fs                     0.2.0
s3transfer               0.1.13
scipy                    1.1.0
seaborn                  0.9.0
setuptools               39.0.1
six                      1.12.0
smmap2                   2.0.5
snowballstemmer          1.2.1
soupsieve                1.6.2
Sphinx                   1.8.3
sphinxcontrib-websupport 1.1.0
SQLAlchemy               1.2.15
statsmodels              0.9.0
tables                   3.4.4
testpath                 0.4.2
thrift                   0.11.0
tornado                  5.1.1
traitlets                4.3.2
Typhoon-HIL-API          1.3.0
TyphoonTest              1.2.1
urllib3                  1.24.1
wcwidth                  0.1.7
webencodings             0.5.1
websocket-client         0.54.0
Werkzeug                 0.14.1
win-inet-pton            1.0.1
wrapt                    1.10.11
xarray                   0.11.2
xlrd                     1.2.0
XlsxWriter               1.1.2
xlwt                     1.3.0
xmltodict                0.11.0

[RonnyPfannschmidt]

lets go for the current idea then and take a look at my more complex plan when trouble happens

[nicoddemus]

@RonnyPfannschmidt I see what you mean, but TBH I’m not sure it is worth the trouble because we are only resetting the flag back to its initial state, which has no impact in future maintenance.