rearrange EnvManager build_venv()

so that it is possible to force installation of setuptools and wheel

src/poetry/inspection/info.py

@@ -580,7 +580,7 @@ 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)