nox.virtualenv.InterpreterNotFound: Python interpreter python3.11 not found #1045
Description
I do see following two test failures on a system without Python 3.11 installed:
______________ test_download_python_auto_missing_interpreter[uv] _______________
which = <MagicMock name='which' id='140736074242704'>
uv_install_mock = <MagicMock name='uv_install_python' id='140736074242368'>
pbs_install_mock = <MagicMock name='pbs_install_python' id='140736074242032'>
venv_backend = 'uv'
make_one = <function make_one.<locals>.factory at 0x7fffac270f60>
@pytest.mark.parametrize("venv_backend", ["uv", "venv", "virtualenv"])
@mock.patch(
"nox.virtualenv.pbs_install_python",
return_value="/.local/share/nox/[email protected]/bin/python3.11",
)
@mock.patch(
"nox.virtualenv.uv_install_python",
return_value=True,
)
@mock.patch.object(shutil, "which", return_value=None)
def test_download_python_auto_missing_interpreter(
which: mock.Mock,
uv_install_mock: mock.Mock,
pbs_install_mock: mock.Mock,
venv_backend: str,
make_one: Callable[..., tuple[VirtualEnv, Path]],
) -> None:
venv, _ = make_one(
interpreter="python3.11",
venv_backend=venv_backend,
download_python="auto",
)
> resolved_interpreter = venv._resolved_interpreter
^^^^^^^^^^^^^^^^^^^^^^^^^^
/data/builds/ul-workspace/components/python/nox/build/amd64-3.14/tests/test_virtualenv.py:1455:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = <nox.virtualenv.VirtualEnv object at 0x7fffac270c00>
@property
def _resolved_interpreter(self) -> str:
"""Return the interpreter, appropriately resolved for the platform.
Based heavily on tox's implementation (tox/interpreters.py).
"""
# If there is no assigned interpreter, then use the same one used by
# Nox.
if isinstance(self._resolved, Exception):
raise self._resolved
if self._resolved is not None:
return self._resolved
if self.interpreter is None:
self._resolved = sys.executable
return self._resolved
# Otherwise we need to divine the path to the interpreter. This is
# designed to accept strings in the form of "2", "2.7", "2.7.13",
# "2.7.13-32", "python2", "python2.4", etc.
xy_version = ""
cleaned_interpreter = self.interpreter
# If this is just a X, X.Y, or X.Y.Z string, extract just the X / X.Y
# part and add Python to the front of it.
match = re.match(r"^(?P<xy_ver>\d(\.\d+)?)(\.\d+)?(?P<t>t?)$", self.interpreter)
if match:
xy_version = match.group("xy_ver")
t = match.group("t")
cleaned_interpreter = f"python{xy_version}{t}"
# never -> check for interpreters
if self.download_python == "never":
if resolved := _find_python(cleaned_interpreter, xy_version):
self._resolved = resolved
return self._resolved
# always -> skip check, always install
elif self.download_python == "always" and self.venv_backend == "uv":
if HAS_UV and version.Version("0.4.16") <= UV_VERSION:
uv_python_success = uv_install_python(cleaned_interpreter)
if uv_python_success:
self._resolved = cleaned_interpreter
return self._resolved
elif self.download_python == "always" and self.venv_backend in (
"venv",
"virtualenv",
):
pbs_python_path = pbs_install_python(cleaned_interpreter)
if pbs_python_path:
self._resolved = pbs_python_path
return self._resolved
# auto -> check interpreters -> fallback to installing
else:
if resolved := _find_python(cleaned_interpreter, xy_version):
self._resolved = resolved
return self._resolved
if (
self.venv_backend == "uv"
and HAS_UV
and version.Version("0.4.16") <= UV_VERSION
):
uv_python_success = uv_install_python(cleaned_interpreter)
if uv_python_success:
self._resolved = cleaned_interpreter
return self._resolved
elif self.venv_backend in ("venv", "virtualenv"):
pbs_python_path = pbs_install_python(cleaned_interpreter)
if pbs_python_path:
self._resolved = pbs_python_path
return self._resolved
self._resolved = InterpreterNotFound(self.interpreter)
> raise self._resolved
E nox.virtualenv.InterpreterNotFound: Python interpreter python3.11 not found
/data/builds/ul-workspace/components/python/nox/build/amd64-3.14/nox/virtualenv.py:767: InterpreterNotFound
___________ test_download_python_always_preexisting_interpreter[uv] ____________
which = <MagicMock name='which' id='140736071413984'>
uv_install_mock = <MagicMock name='uv_install_python' id='140736071413648'>
pbs_install_mock = <MagicMock name='pbs_install_python' id='140736071417008'>
venv_backend = 'uv'
make_one = <function make_one.<locals>.factory at 0x7fffac234eb0>
@pytest.mark.parametrize("venv_backend", ["uv", "venv", "virtualenv"])
@mock.patch(
"nox.virtualenv.pbs_install_python",
return_value="/.local/share/nox/[email protected]/bin/python3.11",
)
@mock.patch(
"nox.virtualenv.uv_install_python",
return_value=True,
)
@mock.patch.object(shutil, "which", return_value="/usr/bin/python3.11")
def test_download_python_always_preexisting_interpreter(
which: mock.Mock,
uv_install_mock: mock.Mock,
pbs_install_mock: mock.Mock,
venv_backend: str,
make_one: Callable[..., tuple[VirtualEnv, Path]],
) -> None:
venv, _ = make_one(
interpreter="python3.11",
venv_backend=venv_backend,
download_python="always",
)
> resolved_interpreter = venv._resolved_interpreter
^^^^^^^^^^^^^^^^^^^^^^^^^^
/data/builds/ul-workspace/components/python/nox/build/amd64-3.14/tests/test_virtualenv.py:1494:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = <nox.virtualenv.VirtualEnv object at 0x7fffac235230>
@property
def _resolved_interpreter(self) -> str:
"""Return the interpreter, appropriately resolved for the platform.
Based heavily on tox's implementation (tox/interpreters.py).
"""
# If there is no assigned interpreter, then use the same one used by
# Nox.
if isinstance(self._resolved, Exception):
raise self._resolved
if self._resolved is not None:
return self._resolved
if self.interpreter is None:
self._resolved = sys.executable
return self._resolved
# Otherwise we need to divine the path to the interpreter. This is
# designed to accept strings in the form of "2", "2.7", "2.7.13",
# "2.7.13-32", "python2", "python2.4", etc.
xy_version = ""
cleaned_interpreter = self.interpreter
# If this is just a X, X.Y, or X.Y.Z string, extract just the X / X.Y
# part and add Python to the front of it.
match = re.match(r"^(?P<xy_ver>\d(\.\d+)?)(\.\d+)?(?P<t>t?)$", self.interpreter)
if match:
xy_version = match.group("xy_ver")
t = match.group("t")
cleaned_interpreter = f"python{xy_version}{t}"
# never -> check for interpreters
if self.download_python == "never":
if resolved := _find_python(cleaned_interpreter, xy_version):
self._resolved = resolved
return self._resolved
# always -> skip check, always install
elif self.download_python == "always" and self.venv_backend == "uv":
if HAS_UV and version.Version("0.4.16") <= UV_VERSION:
uv_python_success = uv_install_python(cleaned_interpreter)
if uv_python_success:
self._resolved = cleaned_interpreter
return self._resolved
elif self.download_python == "always" and self.venv_backend in (
"venv",
"virtualenv",
):
pbs_python_path = pbs_install_python(cleaned_interpreter)
if pbs_python_path:
self._resolved = pbs_python_path
return self._resolved
# auto -> check interpreters -> fallback to installing
else:
if resolved := _find_python(cleaned_interpreter, xy_version):
self._resolved = resolved
return self._resolved
if (
self.venv_backend == "uv"
and HAS_UV
and version.Version("0.4.16") <= UV_VERSION
):
uv_python_success = uv_install_python(cleaned_interpreter)
if uv_python_success:
self._resolved = cleaned_interpreter
return self._resolved
elif self.venv_backend in ("venv", "virtualenv"):
pbs_python_path = pbs_install_python(cleaned_interpreter)
if pbs_python_path:
self._resolved = pbs_python_path
return self._resolved
self._resolved = InterpreterNotFound(self.interpreter)
> raise self._resolved
E nox.virtualenv.InterpreterNotFound: Python interpreter python3.11 not found
/data/builds/ul-workspace/components/python/nox/build/amd64-3.14/nox/virtualenv.py:767: InterpreterNotFound
OS: OpenIndiana
nox: 2025.11.12
Python: 3.14.2