python 3.12 in pipelines

.github/workflows/main.yml

@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         os: [Ubuntu, macOS, Windows]
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12-dev"]
         include:
           - os: Ubuntu
             image: ubuntu-22.04
@@ -117,7 +117,8 @@ jobs:
           ref: refs/tags/${{ steps.poetry-plugin-export-version.outputs.version }}
 
       - name: Run pytest (poetry-plugin-export)
-        run: poetry run pytest -v poetry-plugin-export/tests/
+        working-directory: ./poetry-plugin-export
+        run: poetry run -C .. pytest -v
 
       - name: Check for clean working tree
         run: |

docs/configuration.md

@@ -375,6 +375,12 @@ If set to `true` the `--no-setuptools` parameter is passed to `virtualenv` on cr
 means when a new virtual environment is created, `setuptools` will not be installed in the environment. Poetry, for its
 internal operations, does not require `setuptools` and this can safely be set to `true`.
 
+For environments using python 3.12 or later, `virtualenv` defaults to not
+installing `setuptools` when creating a virtual environment.
+In such environments this poetry configuration option therefore has no effect:
+`setuptools` is not installed either way.
+If your project relies on `setuptools`, you should declare it as a dependency.
+
 {{% warning %}}
 Some development tools like IDEs, make an assumption that `setuptools` (and other) packages are always present and
 available within a virtual environment. This can cause some features in these tools to not work as expected.

pyproject.toml

@@ -57,7 +57,7 @@ tomli = { version = "^2.0.1", python = "<3.11" }
 tomlkit = ">=0.11.4,<1.0.0"
 # trove-classifiers uses calver, so version is unclamped
 trove-classifiers = ">=2022.5.19"
-virtualenv = "^20.22.0"
+virtualenv = "^20.23.0"
 xattr = { version = "^0.10.0", markers = "sys_platform == 'darwin'" }
 
 [tool.poetry.group.dev.dependencies]

src/poetry/inspection/info.py

@@ -579,7 +579,7 @@ def get_pep517_metadata(path: Path) -> PackageInfo:
             return info
 
     with ephemeral_environment(
-        flags={"no-pip": False, "no-setuptools": False, "no-wheel": False}
+        flags={"no-pip": False, "setuptools": "bundle", "wheel": "bundle"}
     ) as venv:
         # TODO: cache PEP 517 build environment corresponding to each project venv
         dest_dir = venv.path.parent / "dist"

src/poetry/utils/env/__init__.py

@@ -41,7 +41,7 @@
 @contextmanager
 def ephemeral_environment(
     executable: Path | None = None,
-    flags: dict[str, bool] | None = None,
+    flags: dict[str, str | bool] | None = None,
 ) -> Iterator[VirtualEnv]:
     with temporary_directory() as tmp_dir:
         # TODO: cache PEP 517 build environment corresponding to each project venv

src/poetry/utils/env/env_manager.py

@@ -612,35 +612,40 @@ def build_venv(
         cls,
         path: Path,
         executable: Path | None = None,
-        flags: dict[str, bool] | None = None,
+        flags: dict[str, str | bool] | None = None,
         with_pip: bool | None = None,
         with_wheel: bool | None = None,
         with_setuptools: bool | None = None,
         prompt: str | None = None,
     ) -> virtualenv.run.session.Session:
-        if WINDOWS:
-            path = get_real_windows_path(path)
-            executable = get_real_windows_path(executable) if executable else None
-
         flags = flags or {}
 
-        flags["no-pip"] = (
-            not with_pip if with_pip is not None else flags.pop("no-pip", True)
-        )
+        if with_pip is not None:
+            flags["no-pip"] = not with_pip
 
-        flags["no-setuptools"] = (
-            not with_setuptools
-            if with_setuptools is not None
-            else flags.pop("no-setuptools", True)
-        )
+        if with_wheel is not None:
+            wheel_flags: dict[str, str | bool] = (
+                {"wheel": "bundle"} if with_wheel else {"no-wheel": True}
+            )
+            flags.update(wheel_flags)
 
-        # we want wheels to be enabled when pip is required and it has not been
-        # explicitly disabled
-        flags["no-wheel"] = (
-            not with_wheel
-            if with_wheel is not None
-            else flags.pop("no-wheel", flags["no-pip"])
-        )
+        if with_setuptools is not None:
+            setuptools_flags: dict[str, str | bool] = (
+                {"setuptools": "bundle"} if with_setuptools else {"no-setuptools": True}
+            )
+            flags.update(setuptools_flags)
+
+        flags.setdefault("no-pip", True)
+
+        if "setuptools" not in flags and "no-setuptools" not in flags:
+            flags["no-setuptools"] = True
+
+        if "wheel" not in flags and "no-wheel" not in flags:
+            flags["no-wheel"] = True
+
+        if WINDOWS:
+            path = get_real_windows_path(path)
+            executable = get_real_windows_path(executable) if executable else None
 
         executable_str = None if executable is None else executable.resolve().as_posix()
 
@@ -658,6 +663,9 @@ def build_venv(
             if value is True:
                 args.append(f"--{flag}")
 
+            elif value is not False:
+                args.append(f"--{flag}={value}")
+
         args.append(str(path))
 
         cli_result = virtualenv.cli_run(args)

tests/utils/test_env.py

@@ -1489,18 +1489,21 @@ def test_env_system_packages_are_relative_to_lib(
 @pytest.mark.parametrize(
     ("flags", "packages"),
     [
-        ({"no-pip": False}, {"pip", "wheel"}),
+        ({"no-pip": False}, {"pip"}),
         ({"no-pip": False, "no-wheel": True}, {"pip"}),
+        ({"no-pip": False, "no-wheel": False}, {"pip", "wheel"}),
         ({"no-pip": True}, set()),
         ({"no-setuptools": False}, {"setuptools"}),
         ({"no-setuptools": True}, set()),
+        ({"setuptools": "bundle"}, {"setuptools"}),
         ({"no-pip": True, "no-setuptools": False}, {"setuptools"}),
         ({"no-wheel": False}, {"wheel"}),
+        ({"wheel": "bundle"}, {"wheel"}),
         ({}, set()),
     ],
 )
 def test_env_no_pip(
-    tmp_path: Path, poetry: Poetry, flags: dict[str, bool], packages: set[str]
+    tmp_path: Path, poetry: Poetry, flags: dict[str, str | bool], packages: set[str]
 ) -> None:
     venv_path = tmp_path / "venv"
     EnvManager(poetry).build_venv(path=venv_path, flags=flags)
@@ -1513,6 +1516,14 @@ def test_env_no_pip(
         if package.name != "sqlite3"
     }
 
+    # For python >= 3.12, virtualenv defaults to "--no-setuptools" and "--no-wheel"
+    # behaviour, so setting these values to False becomes meaningless.
+    if sys.version_info >= (3, 12):
+        if not flags.get("no-setuptools", True):
+            packages.discard("setuptools")
+        if not flags.get("no-wheel", True):
+            packages.discard("wheel")
+
     assert installed_packages == packages