Fixed issue when @parametrize_with_cases was used on a fixture in a…

… `conftest.py`. Fixes #196

pytest_cases/plugin.py

@@ -1408,12 +1408,14 @@ def pytest_addoption(parser):
 PYTEST_CONFIG = None  # type: _pytest.config.Config
 
 
-# @hookspec(historic=True)
-def pytest_configure(config):
-    # store the received config object for future use; see #165 & #166
+def pytest_load_initial_conftests(early_config):
+    # store the received config object for future use; see #165 #166 #196
     global PYTEST_CONFIG
-    PYTEST_CONFIG = config
+    PYTEST_CONFIG = early_config
+
 
+# @hookspec(historic=True)
+def pytest_configure(config):
     # validate the config
     allowed_values = ('normal', 'skip')
     reordering_choice = config.getoption(_OPTION_NAME)

pytest_cases/tests/cases/issues/issue_196/conftest.py

@@ -0,0 +1,11 @@
+from pytest_cases import fixture, parametrize_with_cases
+
+
+def case_a():
+    return 1
+
+
+@fixture
+@parametrize_with_cases("a", cases=case_a)
+def dummy_fixture(a):
+    return a + 1

pytest_cases/tests/cases/issues/issue_196/test_issue_196.py

@@ -0,0 +1,3 @@
+def test_foo(dummy_fixture):
+    """Before the fix this test would not even start because a conftest loading error was appearing"""
+    assert dummy_fixture == 2