Deprecate rmm._lib (#1713)

Follows up #1676 to add deprecation warnings to the `rmm._lib` sub package.

Authors:
  - Matthew Murray (https://github.com/Matt711)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #1713

python/rmm/rmm/__init__.py

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import warnings
+
 from rmm import mr
 from rmm._version import __git_commit__, __version__
 from rmm.mr import disable_logging, enable_logging, get_log_filenames
@@ -58,6 +60,12 @@ def __getattr__(name):
     if name == "_lib":
         import importlib
 
+        warnings.warn(
+            "The `rmm._lib` module is deprecated in will be removed in a future release. Use `rmm.pylibrmm` instead.",
+            FutureWarning,
+            stacklevel=2,
+        )
+
         module = importlib.import_module("rmm.pylibrmm")
         return module
     else:

python/rmm/rmm/_lib/__init__.py

@@ -12,4 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import warnings
+
 from rmm.pylibrmm import *
+
+warnings.warn(
+    "The `rmm._lib` module is deprecated in will be removed in a future release. Use `rmm.pylibrmm` instead.",
+    FutureWarning,
+    stacklevel=2,
+)

python/rmm/rmm/tests/test_rmm.py

@@ -1076,3 +1076,9 @@ def test_available_device_memory():
     assert initial_memory[1] == final_memory[1]
     assert initial_memory[0] > 0
     assert final_memory[0] > 0
+
+
+# TODO: Remove test when rmm._lib is removed in 25.02
+def test_deprecate_rmm_lib():
+    with pytest.warns(FutureWarning):
+        rmm._lib.device_buffer.DeviceBuffer(size=100)