fix: support broken uv (via pyenv)

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

nox/virtualenv.py

@@ -44,7 +44,7 @@
     "HAS_UV",
     "OPTIONAL_VENVS",
     "UV",
-    "UV_PYTHON_SUPPORT",
+    "UV_VERSION",
     "CondaEnv",
     "InterpreterNotFound",
     "PassthroughEnv",
@@ -81,7 +81,7 @@ def __dir__() -> list[str]:
 )
 
 
-def find_uv() -> tuple[bool, str]:
+def find_uv() -> tuple[bool, str, version.Version]:
     uv_on_path = shutil.which("uv")
 
     # Look for uv in Nox's environment, to handle `pipx install nox[uv]`.
@@ -90,22 +90,25 @@ def find_uv() -> tuple[bool, str]:
 
         uv_bin = find_uv_bin()
 
-        # If the returned value is the same as calling "uv" already, don't
-        # expand (simpler logging)
-        if uv_on_path and Path(uv_bin).samefile(uv_on_path):
-            return True, "uv"
+        uv_vers = uv_version(uv_bin)
+        if uv_vers > version.Version("0"):
+            # If the returned value is the same as calling "uv" already, don't
+            # expand (simpler logging)
+            if uv_on_path and Path(uv_bin).samefile(uv_on_path):
+                return True, "uv", uv_vers
 
-        return True, uv_bin
+            return True, uv_bin, uv_vers
 
     # Fall back to PATH.
-    return uv_on_path is not None, "uv"
+    uv_vers = uv_version("uv")
+    return uv_on_path is not None and uv_vers > version.Version("0"), "uv", uv_vers
 
 
-def uv_version() -> version.Version:
+def uv_version(uv_bin: str) -> version.Version:
     """Returns uv's version defaulting to 0.0 if uv is not available"""
     try:
         ret = subprocess.run(
-            [UV, "version", "--output-format", "json"],
+            [uv_bin, "version", "--output-format", "json"],
             check=False,
             text=True,
             capture_output=True,
@@ -130,10 +133,7 @@ def uv_install_python(python_version: str) -> bool:
     return ret.returncode == 0
 
 
-HAS_UV, UV = find_uv()
-# supported since uv 0.3 but 0.4.16 is the first version that doesn't cause
-# issues for nox with pypy/cpython confusion
-UV_PYTHON_SUPPORT = uv_version() >= version.Version("0.4.16")
+HAS_UV, UV, UV_VERSION = find_uv()
 
 
 class InterpreterNotFound(OSError):
@@ -612,8 +612,12 @@ def _resolved_interpreter(self) -> str:
             self._resolved = cleaned_interpreter
             return self._resolved
 
+        # Supported since uv 0.3 but 0.4.16 is the first version that doesn't cause
+        # issues for nox with pypy/cpython confusion
         if (
-            self.venv_backend == "uv" and HAS_UV and UV_PYTHON_SUPPORT
+            self.venv_backend == "uv"
+            and HAS_UV
+            and version.Version("0.4.16") <= UV_VERSION
         ):  # pragma: nocover
             uv_python_success = uv_install_python(cleaned_interpreter)
             if uv_python_success:

tests/test_virtualenv.py

@@ -722,12 +722,14 @@ def test_create_reuse_uv_environment(
 
 
 @pytest.mark.parametrize(
-    ("which_result", "find_uv_bin_result", "found", "path"),
+    ("which_result", "find_uv_bin_result", "found", "path", "vers", "vers_rc"),
     [
-        ("/usr/bin/uv", UV_IN_PIPX_VENV, True, UV_IN_PIPX_VENV),
-        ("/usr/bin/uv", None, True, "uv"),
-        (None, UV_IN_PIPX_VENV, True, UV_IN_PIPX_VENV),
-        (None, None, False, "uv"),
+        ("/usr/bin/uv", UV_IN_PIPX_VENV, True, UV_IN_PIPX_VENV, "0.5.0", 0),
+        ("/usr/bin/uv", None, True, "uv", "0.6.0", 0),
+        ("/usr/bin/uv", None, False, "uv", "0.0.0", 0),
+        ("/usr/bin/uv", None, False, "uv", "0.6.0", 1),
+        (None, UV_IN_PIPX_VENV, True, UV_IN_PIPX_VENV, "0.5.0", 0),
+        (None, None, False, "uv", "0.5.0", 0),
     ],
 )
 def test_find_uv(
@@ -736,19 +738,34 @@ def test_find_uv(
     find_uv_bin_result: str | None,
     found: bool,
     path: str,
+    vers: str,
+    vers_rc: int,
 ) -> None:
     def find_uv_bin() -> str:
         if find_uv_bin_result:
             return find_uv_bin_result
         raise FileNotFoundError()
 
+    def mock_run(*args: object, **kwargs: object) -> subprocess.CompletedProcess[str]:
+        return subprocess.CompletedProcess(
+            args=["uv", "version", "--output-format", "json"],
+            stdout=f'{{"version": "{vers}", "commit_info": null}}',
+            returncode=vers_rc,
+        )
+
+    monkeypatch.setattr(subprocess, "run", mock_run)
+
     monkeypatch.setattr(shutil, "which", lambda _: which_result)
     monkeypatch.setattr(Path, "samefile", lambda a, b: a == b)
     monkeypatch.setitem(
         sys.modules, "uv", types.SimpleNamespace(find_uv_bin=find_uv_bin)
     )
 
-    assert nox.virtualenv.find_uv() == (found, path)
+    assert nox.virtualenv.find_uv() == (
+        found,
+        path,
+        version.Version(vers if vers_rc == 0 else "0"),
+    )
 
 
 @pytest.mark.parametrize(
@@ -773,15 +790,17 @@ def mock_run(*args: object, **kwargs: object) -> subprocess.CompletedProcess[str
         )
 
     monkeypatch.setattr(subprocess, "run", mock_run)
-    assert nox.virtualenv.uv_version() == version.Version(expected_result)
+    assert nox.virtualenv.uv_version(nox.virtualenv.UV) == version.Version(
+        expected_result
+    )
 
 
 def test_uv_version_no_uv(monkeypatch: pytest.MonkeyPatch) -> None:
     def mock_exception(*args: object, **kwargs: object) -> NoReturn:
         raise FileNotFoundError
 
     monkeypatch.setattr(subprocess, "run", mock_exception)
-    assert nox.virtualenv.uv_version() == version.Version("0.0")
+    assert nox.virtualenv.uv_version(nox.virtualenv.UV) == version.Version("0.0")
 
 
 @pytest.mark.parametrize(
@@ -1064,7 +1083,7 @@ def special_run(cmd: str, *args: str, **kwargs: object) -> TextProcessResult:  #
 
 
 @mock.patch("nox.virtualenv._PLATFORM", new="win32")
-@mock.patch("nox.virtualenv.UV_PYTHON_SUPPORT", new=False)
+@mock.patch("nox.virtualenv.UV_VERSION", new=version.Version("0.3"))
 def test__resolved_interpreter_windows_path_and_version(
     make_one: Callable[..., tuple[VirtualEnv, Path]],
     patch_sysfind: Callable[..., None],
@@ -1093,7 +1112,7 @@ def test__resolved_interpreter_windows_path_and_version(
 @pytest.mark.parametrize("sysfind_result", [r"c:\python37-x64\python.exe", None])
 @pytest.mark.parametrize("sysexec_result", ["3.7.3\\n", RAISE_ERROR])
 @mock.patch("nox.virtualenv._PLATFORM", new="win32")
-@mock.patch("nox.virtualenv.UV_PYTHON_SUPPORT", new=False)
+@mock.patch("nox.virtualenv.UV_VERSION", new=version.Version("0.3"))
 def test__resolved_interpreter_windows_path_and_version_fails(
     input_: str,
     sysfind_result: None | str,