CI: Cache libcudf JIT kernels in C++ tests

.github/workflows/pr.yaml

@@ -310,6 +310,9 @@ jobs:
     with:
       build_type: pull-request
       script: ci/test_cpp.sh
+      cache-paths: .cache/libcudf
+      cache-key-prefix: libcudf-rtcx-v1
+      cache-environment: LIBCUDF_KERNEL_CACHE_PATH=.cache/libcudf
       # https://github.com/NVIDIA/cudf/issues/23498
       matrix_filter: map(select(.GPU != "gb300" and .GPU != "gh200"))
   conda-python-build:

.github/workflows/test.yaml

@@ -54,6 +54,9 @@ jobs:
       date: ${{ inputs.date }}
       script: ci/test_cpp.sh
       sha: ${{ inputs.sha }}
+      cache-paths: .cache/libcudf
+      cache-key-prefix: libcudf-rtcx-v1
+      cache-environment: LIBCUDF_KERNEL_CACHE_PATH=.cache/libcudf
       # https://github.com/NVIDIA/cudf/issues/23498
       matrix_filter: map(select(.GPU != "gb300" and .GPU != "gh200"))
   conda-cpp-benchmark-tests:

ci/release/update-version.sh

@@ -158,6 +158,7 @@ DEPENDENCIES=(
   libcudf
   libcudf-example
   libcudf-streaming
+  libcudf-streaming-tests
   libcudf-tests
   libcudf_kafka
   libkvikio

ci/test_cpp_common.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
@@ -33,6 +33,15 @@ RESULTS_DIR=${RAPIDS_TESTS_DIR:-"$(mktemp -d)"}
 RAPIDS_TESTS_DIR=${RAPIDS_TESTS_DIR:-"${RESULTS_DIR}/test-results"}/
 mkdir -p "${RAPIDS_TESTS_DIR}"
 
+# CI provides LIBCUDF_KERNEL_CACHE_PATH through the reusable workflow's cache-environment input.
+# Resolve a workspace-relative value before CTest changes its working directory.
+LIBCUDF_KERNEL_CACHE_PATH="${LIBCUDF_KERNEL_CACHE_PATH:-.cache/libcudf}"
+if [[ "${LIBCUDF_KERNEL_CACHE_PATH}" != /* ]]; then
+  LIBCUDF_KERNEL_CACHE_PATH="$(realpath -m "${LIBCUDF_KERNEL_CACHE_PATH}")"
+fi
+export LIBCUDF_KERNEL_CACHE_PATH
+mkdir -p "${LIBCUDF_KERNEL_CACHE_PATH}"
+
 rapids-print-env
 
 rapids-logger "Check GPU usage"

dependencies.yaml

@@ -1137,7 +1137,7 @@ dependencies:
           - libcudf-example==26.12.*,>=0.0.0a0
           - libcudf_kafka==26.12.*,>=0.0.0a0
           - libcudf-tests==26.12.*,>=0.0.0a0
-          - libcudf-streaming-tests==26.10.*,>=0.0.0a0
+          - libcudf-streaming-tests==26.12.*,>=0.0.0a0
   test_python_common:
     common:
       - output_types: [conda, requirements, constraints, pyproject]