QST: how to run Pandas tests involving Numba on installed package
- [x] I have searched the [[pandas] tag](https://stackoverflow.com/questions/tagged/pandas) on StackOverflow for similar questions.

- [ ] I have asked my usage related question on [StackOverflow](https://stackoverflow.com).

---

#### Question about pandas

I am trying to run the Pandas tests involving Numba like so:

```shell
pytest --pyargs pandas.tests.window.test_numba
```

But unfortunately all 49 tests fail with the same error:

```
______________________________________________________________ ERROR at setup of test_use_global_config _______________________________________________________________

self = <_pytest.config.Config object at 0x7fdf2e856190>, name = 'only_slow', default = <NOTSET>, skip = False

    def getoption(self, name: str, default=notset, skip: bool = False):
        """Return command line option value.

        :param name: Name of the option.  You may also specify
            the literal ``--OPT`` option instead of the "dest" option name.
        :param default: Default value if no option of that name exists.
        :param skip: If True, raise pytest.skip if option does not exists
            or has a None value.
        """
        name = self._opt2dest.get(name, name)
        try:
>           val = getattr(self.option, name)
E           AttributeError: 'Namespace' object has no attribute 'only_slow'

miniconda3/envs/pandas-dev/lib/python3.8/site-packages/_pytest/config/__init__.py:1460: AttributeError

The above exception was the direct cause of the following exception:

item = <Function test_use_global_config>

    def pytest_runtest_setup(item):
        if "slow" in item.keywords and item.config.getoption("--skip-slow"):
            pytest.skip("skipping due to --skip-slow")

>       if "slow" not in item.keywords and item.config.getoption("--only-slow"):
E       ValueError: no option named 'only_slow'

miniconda3/envs/pandas-dev/lib/python3.8/site-packages/pandas/conftest.py:79: ValueError
```

Perhaps I am not running the tests correctly?