Fix --help/--version crash in a partially configured app

Fix #1106.

Author: bluetech

pytest_django/plugin.py

@@ -362,8 +362,15 @@ def _get_option_with_source(
 
 @pytest.hookimpl(trylast=True)
 def pytest_configure(config: pytest.Config) -> None:
-    # Allow Django settings to be configured in a user pytest_configure call,
-    # but make sure we call django.setup()
+    if config.getoption("version", 0) > 0 or config.getoption("help", False):
+        return
+
+    # Normally Django is set up in `pytest_load_initial_conftests`, but we also
+    # allow users to not set DJANGO_SETTINGS_MODULE/`--ds` and instead
+    # configure the Django settings in a `pytest_configure` hookimpl using e.g.
+    # `settings.configure(...)`. In this case, the `_setup_django` call in
+    # `pytest_load_initial_conftests` only partially initializes Django, and
+    # it's fully initialized here.
     _setup_django(config)
 
 

tests/test_manage_py_scan.py

@@ -144,6 +144,37 @@ def test_django_project_found_invalid_settings_version(
     result.stdout.fnmatch_lines(["*usage:*"])
 
 
+@pytest.mark.django_project(project_root="django_project_root", create_manage_py=True)
+def test_django_project_late_settings_version(
+    django_pytester: DjangoPytester,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Late configuration should not cause an error with --help or --version."""
+    monkeypatch.delenv("DJANGO_SETTINGS_MODULE")
+    django_pytester.makepyfile(
+        t="WAT = 1",
+    )
+    django_pytester.makeconftest(
+        """
+        import os
+
+        def pytest_configure():
+            os.environ.setdefault('DJANGO_SETTINGS_MODULE', 't')
+            from django.conf import settings
+            settings.WAT
+        """
+    )
+
+    result = django_pytester.runpytest_subprocess("django_project_root", "--version", "--version")
+    assert result.ret == 0
+
+    result.stdout.fnmatch_lines(["*This is pytest version*"])
+
+    result = django_pytester.runpytest_subprocess("django_project_root", "--help")
+    assert result.ret == 0
+    result.stdout.fnmatch_lines(["*usage:*"])
+
+
 @pytest.mark.django_project(project_root="django_project_root", create_manage_py=True)
 def test_runs_without_error_on_long_args(django_pytester: DjangoPytester) -> None:
     django_pytester.create_test_module(