Check that the cache is writable in _main()

This avoid code duplication (for the wheel and http
cache) and repeated warnings.

news/7488.bugfix

@@ -0,0 +1,2 @@
+Effectively disable the wheel cache when it is not writable, as is the
+case with the http cache.

src/pip/_internal/cli/base_command.py

@@ -31,6 +31,7 @@ from pip._internal.exceptions import (
     UninstallationError,
 )
 from pip._internal.utils.deprecation import deprecated
+from pip._internal.utils.filesystem import check_path_owner
 from pip._internal.utils.logging import BrokenStdoutLoggingError, setup_logging
 from pip._internal.utils.misc import get_prog
 from pip._internal.utils.temp_dir import global_tempdir_manager
@@ -168,6 +169,18 @@ class Command(CommandContextMixIn):
                 )
                 sys.exit(VIRTUALENV_NOT_FOUND)
 
+        if options.cache_dir:
+            if not check_path_owner(options.cache_dir):
+                logger.warning(
+                    "The directory '%s' or its parent directory is not owned "
+                    "or is not writable by the current user. The cache "
+                    "has been disabled. Check the permissions and owner of "
+                    "that directory. If executing pip with sudo, you may want "
+                    "sudo's -H flag.",
+                    options.cache_dir,
+                )
+                options.cache_dir = None
+
         try:
             status = self.run(options, args)
             # FIXME: all commands should return an exit status

src/pip/_internal/commands/download.py

@@ -11,7 +11,6 @@ from pip._internal.cli.cmdoptions import make_target_python
 from pip._internal.cli.req_command import RequirementCommand
 from pip._internal.req import RequirementSet
 from pip._internal.req.req_tracker import get_requirement_tracker
-from pip._internal.utils.filesystem import check_path_owner
 from pip._internal.utils.misc import ensure_dir, normalize_path, write_output
 from pip._internal.utils.temp_dir import TempDirectory
 
@@ -99,16 +98,6 @@ class DownloadCommand(RequirementCommand):
             target_python=target_python,
         )
         build_delete = (not (options.no_clean or options.build_dir))
-        if options.cache_dir and not check_path_owner(options.cache_dir):
-            logger.warning(
-                "The directory '%s' or its parent directory is not owned "
-                "by the current user and caching wheels has been "
-                "disabled. check the permissions and owner of that "
-                "directory. If executing pip with sudo, you may want "
-                "sudo's -H flag.",
-                options.cache_dir,
-            )
-            options.cache_dir = None
 
         with get_requirement_tracker() as req_tracker, TempDirectory(
             options.build_dir, delete=build_delete, kind="download"

src/pip/_internal/commands/install.py

@@ -34,7 +34,7 @@ from pip._internal.req import RequirementSet, install_given_reqs
 from pip._internal.req.req_tracker import get_requirement_tracker
 from pip._internal.utils.deprecation import deprecated
 from pip._internal.utils.distutils_args import parse_distutils_args
-from pip._internal.utils.filesystem import check_path_owner, test_writable_dir
+from pip._internal.utils.filesystem import test_writable_dir
 from pip._internal.utils.misc import (
     ensure_dir,
     get_installed_version,
@@ -330,17 +330,6 @@ class InstallCommand(RequirementCommand):
         build_delete = (not (options.no_clean or options.build_dir))
         wheel_cache = WheelCache(options.cache_dir, options.format_control)
 
-        if options.cache_dir and not check_path_owner(options.cache_dir):
-            logger.warning(
-                "The directory '%s' or its parent directory is not owned "
-                "by the current user and caching wheels has been "
-                "disabled. check the permissions and owner of that "
-                "directory. If executing pip with sudo, you may want "
-                "sudo's -H flag.",
-                options.cache_dir,
-            )
-            options.cache_dir = None
-
         with get_requirement_tracker() as req_tracker, TempDirectory(
             options.build_dir, delete=build_delete, kind="install"
         ) as directory:

src/pip/_internal/network/session.py

@@ -27,7 +27,6 @@ from pip._internal.network.auth import MultiDomainBasicAuth
 from pip._internal.network.cache import SafeFileCache
 # Import ssl from compat so the initial import occurs in only one place.
 from pip._internal.utils.compat import has_tls, ipaddress
-from pip._internal.utils.filesystem import check_path_owner
 from pip._internal.utils.glibc import libc_ver
 from pip._internal.utils.misc import (
     build_url_from_netloc,
@@ -264,19 +263,6 @@ class PipSession(requests.Session):
             backoff_factor=0.25,
         )
 
-        # Check to ensure that the directory containing our cache directory
-        # is owned by the user current executing pip. If it does not exist
-        # we will check the parent directory until we find one that does exist.
-        if cache and not check_path_owner(cache):
-            logger.warning(
-                "The directory '%s' or its parent directory is not owned by "
-                "the current user and the cache has been disabled. Please "
-                "check the permissions and owner of that directory. If "
-                "executing pip with sudo, you may want sudo's -H flag.",
-                cache,
-            )
-            cache = None
-
         # We want to _only_ cache responses on securely fetched origins. We do
         # this because we can't validate the response of an insecurely fetched
         # origin, and we don't want someone to be able to poison the cache and

tests/functional/test_wheel.py

@@ -120,6 +120,7 @@ def test_pip_wheel_builds_when_no_binary_set(script, data):
     assert "Building wheel for simple" in str(res), str(res)
 
 
+@pytest.mark.skipif("sys.platform == 'win32'")
 def test_pip_wheel_readonly_cache(script, data, tmpdir):
     cache_dir = tmpdir / "cache"
     cache_dir.mkdir()
@@ -133,7 +134,7 @@ def test_pip_wheel_readonly_cache(script, data, tmpdir):
         allow_stderr_warning=True,
     )
     assert res.returncode == 0
-    assert "caching wheels has been disabled" in str(res), str(res)
+    assert "The cache has been disabled." in str(res), str(res)
 
 
 def test_pip_wheel_builds_editable_deps(script, data):