Expected 'uv_install_python' to be called once. Called 0 times.

[mtelka]

Following two tests are failing. I suspect the reason is that there is no uv installed on this platform (and it cannot be installed using pip install uv):

________________ test_download_python_failed_install[always-uv] ________________
    
uv_install_mock = <MagicMock name='uv_install_python' id='140736105955136'>
pbs_install_mock = <MagicMock name='pbs_install_python' id='140736093799568'>
download_python = 'always', venv_backend = 'uv'
make_one = <function make_one.<locals>.factory at 0x7ffface031f0>
        
    @pytest.mark.parametrize("venv_backend", ["uv", "venv", "virtualenv"])
    @pytest.mark.parametrize("download_python", ["always", "auto"])
    @mock.patch("nox.virtualenv.pbs_install_python", return_value=None)
    @mock.patch("nox.virtualenv.uv_install_python", return_value=False)
    def test_download_python_failed_install(
        uv_install_mock: mock.Mock,
        pbs_install_mock: mock.Mock,
        download_python: str,
        venv_backend: str,
        make_one: Callable[..., tuple[VirtualEnv, Path]],
    ) -> None:
        venv, _ = make_one(
            interpreter="python3.11",
            venv_backend=venv_backend,
            download_python=download_python,
        )
        
        with mock.patch.object(shutil, "which", return_value=None) as _, pytest.raises(
            nox.virtualenv.InterpreterNotFound
        ):
            _ = venv._resolved_interpreter

        if venv_backend == "uv":
>           uv_install_mock.assert_called_once_with("python3.11")

tests/test_virtualenv.py:1533:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
        
self = <MagicMock name='uv_install_python' id='140736105955136'>
args = ('python3.11',), kwargs = {}
msg = "Expected 'uv_install_python' to be called once. Called 0 times."
                   
    def assert_called_once_with(self, /, *args, **kwargs):
        """assert that the mock was called exactly once and that that call was
        with the specified arguments."""
        if not self.call_count == 1: 
            msg = ("Expected '%s' to be called once. Called %s times.%s"
                   % (self._mock_name or 'mock',
                      self.call_count,
                      self._calls_repr()))
>           raise AssertionError(msg)
E           AssertionError: Expected 'uv_install_python' to be called once. Called 0 times.

/usr/lib/python3.9/unittest/mock.py:918: AssertionError
_________________ test_download_python_failed_install[auto-uv] _________________

uv_install_mock = <MagicMock name='uv_install_python' id='140736093610288'>
pbs_install_mock = <MagicMock name='pbs_install_python' id='140736093656688'>
download_python = 'auto', venv_backend = 'uv'
make_one = <function make_one.<locals>.factory at 0x7fffacdc4ee0>

    @pytest.mark.parametrize("venv_backend", ["uv", "venv", "virtualenv"])
    @pytest.mark.parametrize("download_python", ["always", "auto"])
    @mock.patch("nox.virtualenv.pbs_install_python", return_value=None)
    @mock.patch("nox.virtualenv.uv_install_python", return_value=False)
    def test_download_python_failed_install(
        uv_install_mock: mock.Mock,
        pbs_install_mock: mock.Mock,
        download_python: str,
        venv_backend: str,
        make_one: Callable[..., tuple[VirtualEnv, Path]],
    ) -> None:
        venv, _ = make_one(
            interpreter="python3.11",
            venv_backend=venv_backend,
            download_python=download_python,
        )

        with mock.patch.object(shutil, "which", return_value=None) as _, pytest.raises(
            nox.virtualenv.InterpreterNotFound
        ):
            _ = venv._resolved_interpreter

        if venv_backend == "uv":
>           uv_install_mock.assert_called_once_with("python3.11")

tests/test_virtualenv.py:1533:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <MagicMock name='uv_install_python' id='140736093610288'>
args = ('python3.11',), kwargs = {}
msg = "Expected 'uv_install_python' to be called once. Called 0 times."

    def assert_called_once_with(self, /, *args, **kwargs):
        """assert that the mock was called exactly once and that that call was
        with the specified arguments."""
        if not self.call_count == 1:
            msg = ("Expected '%s' to be called once. Called %s times.%s"
                   % (self._mock_name or 'mock',
                      self.call_count,
                      self._calls_repr()))
>           raise AssertionError(msg)
E           AssertionError: Expected 'uv_install_python' to be called once. Called 0 times.

/usr/lib/python3.9/unittest/mock.py:918: AssertionError

OS: OpenIndiana
nox: 2025.11.12
Python: 3.14.2