A fixture with autouse set to False will always be used if it overrides a fixture with autouse set to True #3225

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1. RonnyPfannschmidt

   added

   type: bugproblem that needs to be addressedproblem that needs to be addressed

   topic: fixturesanything involving fixtures directly or indirectlyanything involving fixtures directly or indirectly

   on Feb 15, 2018
2. ceridwen commented on Mar 12, 2018

   

   ceridwen

   on Mar 12, 2018

   Contributor

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   I've encountered what may be another manifestation of this bug, only with parametrization. I'm doing some dynamic fixture creation based on command-line options. An autouse=True session fixture takes this fixture as an argument:

   def pytest_configure(config):
       class DynamicFixturePlugin2(object):
           @pytest.fixture(scope='session', params=['foo, 'bar'] if config.getoption('--foo') else [''])
           def baz(self, request):
               return request.param
       config.pluginmanager.register(DynamicFixturePlugin2(), 'baz-fixture')
   

   I realized that I accidentally created a test that uses that same name as a parameter.

   @pytest.mark.parametrize('baz, ['foo', 'bar'])
   def test(baz, ...):
      ....
   

   This test just so happened to be the first test in the file it was in. If I then invoke pytest with this file as the first item in a list of test files and that test is the first test in that file, then I get the following error:

   ScopeMismatch: You tried to access the 'function' scoped fixture 'baz' with a 'session' scoped request object, involved factories
   conftest.py:141:  def autouse_fixture_that_depends_on_dynamic_fixture(request, baz, ...)
   

   If it's not related, tell me and I'll file a separate bug.
3. jbbqqf commented on May 9, 2026

   

   jbbqqf

   on May 9, 2026 · Hidden as low-quality

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