____________________ ERROR at setup of test_extension_load _____________________

    @pytest.fixture(scope="session")
    def ipython():
        config = tools.default_config()
        config.TerminalInteractiveShell.simple_prompt = True
>       shell = interactiveshell.TerminalInteractiveShell.instance(config=config)

tests/unit/test_magics.py:51:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
.nox/unit-3-8/lib/python3.8/site-packages/traitlets/config/configurable.py:540: in instance
    inst = cls(*args, **kwargs)
.nox/unit-3-8/lib/python3.8/site-packages/IPython/terminal/interactiveshell.py:619: in __init__
    super(TerminalInteractiveShell, self).__init__(*args, **kwargs)
.nox/unit-3-8/lib/python3.8/site-packages/IPython/core/interactiveshell.py:529: in __init__
    self.init_virtualenv()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <IPython.terminal.interactiveshell.TerminalInteractiveShell object at 0x7f4dd066d820>

    def init_virtualenv(self):
        """Add the current virtualenv to sys.path so the user can import modules from it.
        This isn't perfect: it doesn't use the Python interpreter with which the
        virtualenv was built, and it ignores the --no-site-packages option. A
        warning will appear suggesting the user installs IPython in the
        virtualenv, but for many cases, it probably works well enough.

        Adapted from code snippets online.

        http://blog.ufsoft.org/2009/1/29/ipython-and-virtualenv
        """
        if 'VIRTUAL_ENV' not in os.environ:
            # Not in a virtualenv
            return
        elif os.environ["VIRTUAL_ENV"] == "":
            warn("Virtual env path set to '', please check if this is intended.")
            return

        p = Path(sys.executable)
        p_venv = Path(os.environ["VIRTUAL_ENV"])

        # fallback venv detection:
        # stdlib venv may symlink sys.executable, so we can't use realpath.
        # but others can symlink *to* the venv Python, so we can't just use sys.executable.
        # So we just check every item in the symlink tree (generally <= 3)
        paths = [p]
        while p.is_symlink():
>           new_path = p.readlink()
E           AttributeError: 'PosixPath' object has no attribute 'readlink'

.nox/unit-3-8/lib/python3.8/site-packages/IPython/core/interactiveshell.py:788: AttributeError