Update test suite to use virtualenv >= 20.0.0

.github/workflows/ci.yml

@@ -122,7 +122,7 @@ jobs:
         if: matrix.os == 'MacOS'
         run: brew install breezy
 
-      - run: pip install nox 'virtualenv<20' 'setuptools != 60.6.0'
+      - run: pip install nox
 
       # Main check
       - name: Run unit tests
@@ -179,7 +179,7 @@ jobs:
           $acl.AddAccessRule($rule)
           Set-Acl "R:\Temp" $acl
 
-      - run: pip install nox 'virtualenv<20'
+      - run: pip install nox
         env:
           TEMP: "R:\\Temp"
 
@@ -261,7 +261,7 @@ jobs:
       - name: Install Ubuntu dependencies
         run: sudo apt-get install bzr
 
-      - run: pip install nox 'virtualenv<20'
+      - run: pip install nox
 
       - name: Run unit tests
         run: >-

setup.cfg

@@ -63,7 +63,6 @@ xfail_strict = True
 markers =
     network: tests that need network
     incompatible_with_sysconfig
-    incompatible_with_test_venv
     incompatible_with_venv
     no_auto_tempdir_manager
     unit: unit tests

src/pip/_internal/utils/virtualenv.py

@@ -19,7 +19,7 @@ def _running_under_venv() -> bool:
     return sys.prefix != getattr(sys, "base_prefix", sys.prefix)
 
 
-def _running_under_regular_virtualenv() -> bool:
+def _running_under_legacy_virtualenv() -> bool:
     """Checks if sys.real_prefix is set.
 
     This handles virtual environments created with pypa's virtualenv.
@@ -29,8 +29,8 @@ def _running_under_regular_virtualenv() -> bool:
 
 
 def running_under_virtualenv() -> bool:
-    """Return True if we're running inside a virtualenv, False otherwise."""
-    return _running_under_venv() or _running_under_regular_virtualenv()
+    """True if we're running inside a virtual environment, False otherwise."""
+    return _running_under_venv() or _running_under_legacy_virtualenv()
 
 
 def _get_pyvenv_cfg_lines() -> Optional[List[str]]:
@@ -77,7 +77,7 @@ def _no_global_under_venv() -> bool:
     return False
 
 
-def _no_global_under_regular_virtualenv() -> bool:
+def _no_global_under_legacy_virtualenv() -> bool:
     """Check if "no-global-site-packages.txt" exists beside site.py
 
     This mirrors logic in pypa/virtualenv for determining whether system
@@ -98,7 +98,7 @@ def virtualenv_no_global() -> bool:
     if _running_under_venv():
         return _no_global_under_venv()
 
-    if _running_under_regular_virtualenv():
-        return _no_global_under_regular_virtualenv()
+    if _running_under_legacy_virtualenv():
+        return _no_global_under_legacy_virtualenv()
 
     return False

tests/conftest.py

@@ -108,10 +108,6 @@ def pytest_collection_modifyitems(config: Config, items: List[pytest.Function])
             if item.get_closest_marker("network") is not None:
                 item.add_marker(pytest.mark.flaky(reruns=3, reruns_delay=2))
 
-        if item.get_closest_marker("incompatible_with_test_venv") and config.getoption(
-            "--use-venv"
-        ):
-            item.add_marker(pytest.mark.skip("Incompatible with test venv"))
         if (
             item.get_closest_marker("incompatible_with_venv")
             and sys.prefix != sys.base_prefix
@@ -474,9 +470,6 @@ def virtualenv_template(
         ):
             (venv.bin / exe).unlink()
 
-    # Enable user site packages.
-    venv.user_site_packages = True
-
     # Rename original virtualenv directory to make sure
     # it's not reused by mistake from one of the copies.
     venv_template = tmpdir / "venv_template"
@@ -742,3 +735,8 @@ def mock_server() -> Iterator[MockServer]:
 @pytest.fixture
 def proxy(request: pytest.FixtureRequest) -> str:
     return request.config.getoption("proxy")
+
+
+@pytest.fixture
+def enable_user_site(virtualenv: VirtualEnvironment) -> None:
+    virtualenv.user_site_packages = True

tests/functional/test_build_env.py

@@ -204,7 +204,7 @@ def test_build_env_overlay_prefix_has_priority(script: PipTestEnvironment) -> No
     assert result.stdout.strip() == "2.0", str(result)
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_build_env_isolation(script: PipTestEnvironment) -> None:
 
     # Create dummy `pkg` wheel.

tests/functional/test_freeze.py

@@ -862,7 +862,7 @@ def test_freeze_with_requirement_option_package_repeated_multi_file(
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_freeze_user(
     script: PipTestEnvironment, virtualenv: VirtualEnvironment, data: TestData
 ) -> None:
@@ -900,7 +900,7 @@ def test_freeze_path(tmpdir: Path, script: PipTestEnvironment, data: TestData) -
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_freeze_path_exclude_user(
     tmpdir: Path, script: PipTestEnvironment, data: TestData
 ) -> None:

tests/functional/test_install.py

@@ -171,7 +171,7 @@ def test_pep518_allows_missing_requires(
     assert result.files_created
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_pep518_with_user_pip(
     script: PipTestEnvironment, pip_src: Path, data: TestData, common_wheels: Path
 ) -> None:
@@ -2106,7 +2106,7 @@ def test_target_install_ignores_distutils_config_install_prefix(
     result.did_not_create(relative_script_base)
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_user_config_accepted(script: PipTestEnvironment) -> None:
     # user set in the config file is parsed as 0/1 instead of True/False.
     # Check that this doesn't cause a problem.

tests/functional/test_install_reqs.py

@@ -305,8 +305,7 @@ def test_install_local_with_subdirectory(script: PipTestEnvironment) -> None:
     result.assert_installed("version_subpkg.py", editable=False)
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("with_wheel")
+@pytest.mark.usefixtures("enable_user_site", "with_wheel")
 def test_wheel_user_with_prefix_in_pydistutils_cfg(
     script: PipTestEnvironment, data: TestData
 ) -> None: