def test_addopts_from_ini_not_concatenated(self, pytester: Pytester) -> None:
        """`addopts` from ini should not take values from normal args (#4265)."""
        pytester.makeini(
            """
            [pytest]
            addopts=-o
        """
        )
        result = pytester.runpytest("cache_dir=ignored")
        result.stderr.fnmatch_lines(
            [
                f"{pytester._request.config._parser.optparser.prog}: error: "
                f"argument -o/--override-ini: expected one argument (via addopts config)"
            ]
        )
        assert result.ret == _pytest.config.ExitCode.USAGE_ERROR
`addopts` from ini should not take values from normal args (#4265).
testing/test_config.py