CI Add third-party testing of cuml

.github/workflows/pr.yaml

@@ -344,7 +344,7 @@ jobs:
     uses: rapidsai/shared-workflows/.github/workflows/checks.yaml@main
     with:
       enable_check_generated_files: false
-      ignored_pr_jobs: "telemetry-summarize spark-rapids-jni"
+      ignored_pr_jobs: "telemetry-summarize spark-rapids-jni cuml-compat-tests"
   conda-cpp-build:
     needs: checks
     permissions:
@@ -775,6 +775,26 @@ jobs:
       container_image: "rapidsai/ci-conda:26.08-latest"
       script: |
         ci/cudf_pandas_scripts/third-party-integration/test.sh python/cudf/cudf_pandas_tests/third_party_integration_tests/dependencies.yaml
+  cuml-compat-tests:
+    needs: [conda-python-build, conda-python-build-noarch, changed-files]
+    permissions:
+      actions: read
+      contents: read
+      id-token: write
+      packages: read
+      pull-requests: read
+    secrets: inherit # zizmor: ignore[secrets-inherit]
+    uses: rapidsai/shared-workflows/.github/workflows/custom-job.yaml@main
+    if: fromJSON(needs.changed-files.outputs.changed_file_groups).test_python_conda && fromJSON(needs.changed-files.outputs.changed_file_groups).neither_cudf_polars_nor_dask_cudf
+    with:
+      build_type: pull-request
+      branch: ${{ inputs.branch }}
+      date: ${{ inputs.date }}
+      sha: ${{ inputs.sha }}
+      node_type: "gpu-l4-latest-1"
+      continue-on-error: true
+      container_image: "rapidsai/ci-conda:26.06-latest"
+      script: "ci/test_cuml_compat.sh"
   pandas-tests:
     # run the Pandas unit tests using PR branch
     needs: [wheel-build-cudf, changed-files]

.github/workflows/test.yaml

@@ -237,6 +237,24 @@ jobs:
       script: |
         ci/cudf_pandas_scripts/third-party-integration/test.sh python/cudf/cudf_pandas_tests/third_party_integration_tests/dependencies.yaml
       continue-on-error: true
+  cuml-compat-tests:
+    permissions:
+      actions: read
+      contents: read
+      id-token: write
+      packages: read
+      pull-requests: read
+    secrets: inherit # zizmor: ignore[secrets-inherit]
+    uses: rapidsai/shared-workflows/.github/workflows/custom-job.yaml@main
+    with:
+      build_type: ${{ inputs.build_type }}
+      branch: ${{ inputs.branch }}
+      date: ${{ inputs.date }}
+      sha: ${{ inputs.sha }}
+      node_type: "gpu-l4-latest-1"
+      continue-on-error: true
+      container_image: "rapidsai/ci-conda:26.06-latest"
+      script: "ci/test_cuml_compat.sh"
   wheel-tests-cudf-polars:
     permissions:
       actions: read

ci/test_cuml_compat.sh

@@ -0,0 +1,47 @@
+#!/bin/bash
+# SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+cd "$(dirname "$(realpath "${BASH_SOURCE[0]}")")"/../
+source ./ci/test_python_common.sh test_python_cudf test_cuml
+
+# Clone cuml at the matching RAPIDS branch to get test files
+# (the conda package doesn't ship cuml/tests/)
+
+# This makes sure we read RAPIDS_BRANCH from the top level of the repo, no matter
+# what the current working directory is.
+RAPIDS_BRANCH="$(cat "$(dirname "$(realpath "${BASH_SOURCE[0]}")")"/../RAPIDS_BRANCH)"
+rapids-logger "Cloning cuml at branch ${RAPIDS_BRANCH}"
+git clone https://github.com/rapidsai/cuml.git --branch "${RAPIDS_BRANCH}" --depth 1 /tmp/cuml
+
+
+CUML_TESTS_DIR=/tmp/cuml/python/cuml/tests
+
+rapids-logger "pytest cuml cuDF-compat subset"
+
+timeout 15m python -m pytest \
+  --cache-clear \
+  "${CUML_TESTS_DIR}/test_array.py" \
+  "${CUML_TESTS_DIR}/test_compose.py" \
+  "${CUML_TESTS_DIR}/test_input_utils.py" \
+  "${CUML_TESTS_DIR}/test_kneighbors_classifier.py" \
+  "${CUML_TESTS_DIR}/test_kneighbors_regressor.py" \
+  "${CUML_TESTS_DIR}/test_label_encoder.py" \
+  "${CUML_TESTS_DIR}/test_elastic_net.py" \
+  "${CUML_TESTS_DIR}/test_linear_regression.py" \
+  "${CUML_TESTS_DIR}/test_logistic_regression.py" \
+  "${CUML_TESTS_DIR}/test_ridge.py" \
+  "${CUML_TESTS_DIR}/test_metrics.py" \
+  "${CUML_TESTS_DIR}/test_one_hot_encoder.py" \
+  "${CUML_TESTS_DIR}/test_ordinal_encoder.py" \
+  "${CUML_TESTS_DIR}/test_random_forest.py" \
+  "${CUML_TESTS_DIR}/test_reflection.py" \
+  "${CUML_TESTS_DIR}/test_sgd.py" \
+  "${CUML_TESTS_DIR}/test_split.py" \
+  "${CUML_TESTS_DIR}/test_svm.py" \
+  "${CUML_TESTS_DIR}/test_target_encoder.py" \
+  "${CUML_TESTS_DIR}/test_text_feature_extraction.py" \
+  "${CUML_TESTS_DIR}/test_train_test_split.py" \
+  "${CUML_TESTS_DIR}/test_validation.py"

dependencies.yaml

@@ -92,6 +92,10 @@ files:
       - depends_on_libcudf
       - depends_on_numba_cuda
       - depends_on_numba_cuda_mlir
+  test_cuml:
+    output: none
+    includes:
+      - depends_on_cuml
   test_python_pylibcudf:
     output: none
     includes:
@@ -1605,6 +1609,11 @@ dependencies:
       - output_types: conda
         packages:
           - dask-cudf==26.8.*,>=0.0.0a0
+  depends_on_cuml:
+    common:
+      - output_types: conda
+        packages:
+          - cuml==26.8.*,>=0.0.0a0
   depends_on_custreamz:
     common:
       - output_types: conda