Running tox without recreating causes collection error

[nedbat]

Trying to run the edx-cookiecutter tests locally:

% tox
py38 installed: accessible-pygments==0.0.4,alabaster==0.7.13,appdirs==1.4.4,arrow==1.2.3,asgiref==3.7.2,astroid==2.15.6,Babel==2.12.1,beautifulsoup4==4.12.2,binaryornot==0.4.4,bleach==6.0.0,build==0.10.0,certifi==2023.7.22,cffi==1.15.1,chardet==5.1.0,charset-normalizer==3.2.0,click==8.1.6,click-log==0.4.0,code-annotations==1.5.0,cookiecutter==2.2.3,coreapi==2.3.3,coreschema==0.0.4,coverage==7.2.7,cryptography==41.0.3,defusedxml==0.7.1,dill==0.3.7,distlib==0.3.7,Django==3.2.20,django-appconf==1.0.5,django-cors-headers==4.2.0,django-crum==0.7.9,django-dynamic-fixture==3.1.2,django-extensions==3.2.3,django-model-utils==4.3.1,django-rest-swagger==2.2.0,django-statici18n==2.4.0,django-waffle==4.0.0,djangorestframework==3.14.0,doc8==0.11.2,docutils==0.18.1,drf-jwt==1.19.2,edx-auth-backends==4.2.0,-e git+ssh://[email protected]/edx/edx-cookiecutters.git@a70363c0d44a79d2dc6cd11a1650f6f571187c89#egg=edx_cookiecutter_lib&subdirectory=lib,edx-django-release-util==1.3.0,edx-django-utils==5.6.0,edx-drf-extensions==8.8.0,edx-i18n-tools==1.1.0,edx-lint==5.3.4,edx-opaque-keys==2.3.0,edx-rest-api-client==5.6.0,exceptiongroup==1.1.2,filelock==3.12.2,fs==2.4.16,idna==3.4,imagesize==1.4.1,importlib-metadata==6.8.0,importlib-resources==6.0.0,iniconfig==2.0.0,isort==5.12.0,itypes==1.2.0,jaraco.classes==3.3.0,jeepney==0.8.0,Jinja2==3.1.2,keyring==24.2.0,lazy-object-proxy==1.9.0,lxml==4.9.3,Mako==1.2.4,markdown-it-py==3.0.0,MarkupSafe==2.1.3,mccabe==0.7.0,mdurl==0.1.2,more-itertools==9.1.0,mysqlclient==2.2.0,newrelic==8.9.0,oauthlib==3.2.2,openapi-codec==1.3.2,packaging==23.1,path==16.7.1,pbr==5.11.1,pip-tools==7.2.0,pkginfo==1.9.6,platformdirs==3.10.0,pluggy==1.2.0,polib==1.2.0,psutil==5.9.5,py==1.11.0,pycodestyle==2.10.0,pycparser==2.21,pydata-sphinx-theme==0.13.3,pydocstyle==6.3.0,Pygments==2.15.1,PyJWT==2.8.0,pylint==2.17.5,pylint-celery==0.3,pylint-django==2.5.3,pylint-plugin-utils==0.8.2,pymongo==3.13.0,PyNaCl==1.5.0,pyproject_hooks==1.0.0,pytest==7.4.0,pytest-cookies==0.7.0,pytest-cov==4.1.0,pytest-django==4.5.2,python-dateutil==2.8.2,python-slugify==8.0.1,python3-openid==3.2.0,pytz==2023.3,PyYAML==6.0.1,readme-renderer==40.0,requests==2.31.0,requests-oauthlib==1.3.1,requests-toolbelt==1.0.0,restructuredtext-lint==1.4.0,rfc3986==2.0.0,rich==13.4.2,SecretStorage==3.3.3,semantic-version==2.10.0,sh==2.0.4,simplejson==3.19.1,six==1.16.0,slumber==0.7.1,snowballstemmer==2.2.0,social-auth-app-django==5.2.0,social-auth-core==4.4.2,soupsieve==2.4.1,Sphinx==6.2.1,sphinx-book-theme==1.0.1,sphinx-rtd-theme==1.2.2,sphinxcontrib-applehelp==1.0.4,sphinxcontrib-devhelp==1.0.2,sphinxcontrib-htmlhelp==2.0.1,sphinxcontrib-jquery==4.1,sphinxcontrib-jsmath==1.0.1,sphinxcontrib-qthelp==1.0.3,sphinxcontrib-serializinghtml==1.1.5,sqlparse==0.4.4,stevedore==5.1.0,text-unidecode==1.3,tomli==2.0.1,tomlkit==0.12.1,tox==3.28.0,twine==4.0.2,typing_extensions==4.7.1,uritemplate==4.1.1,urllib3==2.0.4,virtualenv==20.24.2,web-fragments==2.1.0,webencodings==0.5.1,WebOb==1.8.7,wrapt==1.15.0,XBlock==1.7.0,xblock-utils==3.3.0,zipp==3.16.1
py38 run-test-pre: PYTHONHASHSEED='4160413870'
py38 run-test: commands[0] | pytest
===================================================================== test session starts =====================================================================
platform darwin -- Python 3.8.17, pytest-7.4.0, pluggy-1.2.0
cachedir: .tox/py38/.pytest_cache
rootdir: /System/Volumes/Data/root/src/edx/src/edx-cookiecutters
configfile: tox.ini
plugins: cookies-0.7.0, cov-4.1.0, django-4.5.2
collected 0 items / 1 error

=========================================================================== ERRORS ============================================================================
________________________________________________________________ ERROR collecting test session ________________________________________________________________
.tox/py38/lib/python3.8/site-packages/django_dynamic_fixture/global_settings.py:61: in get_data_fixture
    if hasattr(settings, 'DDF_DEFAULT_DATA_FIXTURE'):
.tox/py38/lib/python3.8/site-packages/django/conf/__init__.py:82: in __getattr__
    self._setup(name)
.tox/py38/lib/python3.8/site-packages/django/conf/__init__.py:63: in _setup
    raise ImproperlyConfigured(
E   django.core.exceptions.ImproperlyConfigured: Requested setting DDF_DEFAULT_DATA_FIXTURE, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.

During handling of the above exception, another exception occurred:
.tox/py38/lib/python3.8/site-packages/_pytest/config/__init__.py:642: in _importconftest
    mod = import_path(conftestpath, mode=importmode, root=rootpath)
.tox/py38/lib/python3.8/site-packages/_pytest/pathlib.py:565: in import_path
    importlib.import_module(module_name)
/usr/local/pyenv/pyenv/versions/3.8.17/lib/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:961: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:219: in _call_with_frames_removed
    ???
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:961: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:219: in _call_with_frames_removed
    ???
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:671: in _load_unlocked
    ???
<frozen importlib._bootstrap_external>:843: in exec_module
    ???
<frozen importlib._bootstrap>:219: in _call_with_frames_removed
    ???
.tox/py38/lib/python3.8/site-packages/django_dynamic_fixture/__init__.py:17: in <module>
    from django_dynamic_fixture.global_settings import DDF_DEFAULT_DATA_FIXTURE, DDF_FILL_NULLABLE_FIELDS, DDF_FK_MIN_DEPTH, \
.tox/py38/lib/python3.8/site-packages/django_dynamic_fixture/global_settings.py:76: in <module>
    DDF_DEFAULT_DATA_FIXTURE = get_data_fixture(default='sequential')
.tox/py38/lib/python3.8/site-packages/django_dynamic_fixture/global_settings.py:73: in get_data_fixture
    six.reraise(DDFImproperlyConfigured, DDFImproperlyConfigured("DDF_DEFAULT_DATA_FIXTURE (%s) must be 'sequential', 'static_sequential', 'global_sequential', 'random' or 'path.to.CustomDataFixtureClass'." % settings.DDF_DEFAULT_DATA_FIXTURE), sys.exc_info()[2])
.tox/py38/lib/python3.8/site-packages/django/conf/__init__.py:82: in __getattr__
    self._setup(name)
.tox/py38/lib/python3.8/site-packages/django/conf/__init__.py:63: in _setup
    raise ImproperlyConfigured(
E   django.core.exceptions.ImproperlyConfigured: Requested setting DDF_DEFAULT_DATA_FIXTURE, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.
=================================================================== short test summary info ===================================================================
ERROR  - django.core.exceptions.ImproperlyConfigured: Requested setting DDF_DEFAULT_DATA_FIXTURE, but settings are not configured. You must either define the envir...
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
====================================================================== 1 error in 3.71s =======================================================================
ERROR: InvocationError for command /System/Volumes/Data/root/src/edx/src/edx-cookiecutters/.tox/py38/bin/pytest (exited with code 2)
___________________________________________________________________________ summary ___________________________________________________________________________
ERROR:   py38: commands failed

tox -r to recreate the environment works fine.