Build MG C++ tests in libcuml-tests

.github/workflows/pr.yaml

@@ -18,7 +18,6 @@ jobs:
       - clang-tidy
       - conda-cpp-build
       - conda-cpp-tests
-      - build-mg-cpp-tests
       - conda-cpp-checks
       - conda-python-build
       - conda-python-tests-singlegpu
@@ -348,23 +347,6 @@ jobs:
     with:
       build_type: pull-request
       script: ci/test_cpp.sh
-  build-mg-cpp-tests:
-    needs: [conda-cpp-build, 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_cpp
-    with:
-      build_type: pull-request
-      node_type: cpu16
-      arch: amd64
-      container_image: "rapidsai/ci-conda:26.12-latest"
-      script: ci/build_mg_cpp_tests.sh
   conda-cpp-checks:
     needs: conda-cpp-build
     permissions:

.github/workflows/test.yaml

@@ -55,24 +55,6 @@ jobs:
       date: ${{ inputs.date }}
       script: ci/test_cpp.sh
       sha: ${{ inputs.sha }}
-  build-mg-cpp-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: cpu16
-      arch: amd64
-      container_image: "rapidsai/ci-conda:26.12-latest"
-      script: ci/build_mg_cpp_tests.sh
   conda-python-tests-singlegpu:
     permissions:
       actions: read

ci/test_cpp.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-# SPDX-FileCopyrightText: Copyright (c) 2022-2026, NVIDIA CORPORATION.
+# SPDX-FileCopyrightText: Copyright (c) 2022-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 set -euo pipefail
@@ -40,7 +40,8 @@ nvidia-smi
 rapids-logger "Run gtests"
 export GTEST_OUTPUT=xml:${RAPIDS_TESTS_DIR}/
 # Run libcuml gtests from libcuml-tests package
-timeout -v 20m ./ci/run_ctests.sh -j9 && EXITCODE=$? || EXITCODE=$?;
+# Multi-GPU (MG_*) tests require MPI with multiple GPUs to run
+timeout -v 20m ./ci/run_ctests.sh -j9 --exclude-regex '^MG_' && EXITCODE=$? || EXITCODE=$?;
 
 rapids-logger "Test script exiting with value: $EXITCODE"
 exit "${EXITCODE}"

conda/recipes/libcuml/recipe.yaml

@@ -28,7 +28,7 @@ cache:
         export CXXFLAGS=$(echo $CXXFLAGS | sed -E 's@\-fdebug\-prefix\-map[^ ]*@@g')
         set +x
 
-        ./build.sh -n libcuml prims -v --allgpuarch --build-metrics --incl-cache-stats
+        ./build.sh -n libcuml prims cpp-mgtests -v --allgpuarch --build-metrics --incl-cache-stats
       secrets:
         - AWS_ACCESS_KEY_ID
         - AWS_SECRET_ACCESS_KEY
@@ -74,6 +74,7 @@ cache:
       - libcuvs =${{ minor_version }}
       - libraft-headers =${{ minor_version }}
       - librmm =${{ minor_version }}
+      - openmpi # Required for building cpp-mgtests (multi-GPU tests)
       - rapids-logger =0.3
       - treelite ${{ treelite_version }}
       - cuda-cudart-dev
@@ -160,6 +161,7 @@ outputs:
         - rapids-logger =0.3
         - ${{ pin_subpackage("libcuml", exact=True) }}
         - cuda-cudart-dev
+        - openmpi # Required for multi-GPU tests
       run:
         - ${{ pin_compatible("cuda-version", upper_bound="x", lower_bound="x") }}
         - ${{ pin_subpackage("libcuml", exact=True) }}

dependencies.yaml

@@ -91,17 +91,6 @@ files:
       - depends_on_libnvforest
       - test_libcuml
       - test_cpp
-  build_cpp_mg_tests:
-    output: none
-    includes:
-      - common_build
-      - cuda
-      - cuda_version
-      - depends_on_libcuvs
-      - depends_on_libnvforest
-      - depends_on_libraft_headers
-      - depends_on_librmm
-      - build_cpp_mg_tests
   test_integration_bertopic:
     output: none
     includes:
@@ -608,12 +597,6 @@ dependencies:
       - output_types: conda
         packages:
           - *cmake_ver
-  build_cpp_mg_tests:
-    common:
-      - output_types: conda
-        packages:
-          - openmpi
-          - ccache
   test_python:
     specific:
       - output_types: [conda, requirements, pyproject]