CI: prototype persistent pip cache

.github/workflows/pr.yaml

@@ -143,6 +143,7 @@ jobs:
         unit_tests_cudf_pandas:
           - 'python/cudf/cudf/pandas/**'
           - 'ci/cudf_pandas_scripts/run_tests.sh'
+          - 'ci/cudf_pandas_scripts/run_tests_with_pip_cache_prototype.sh'
           - 'ci/utils/get_matrix_values.py'
         test_java:
           - 'java/**'
@@ -310,6 +311,9 @@ 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:
@@ -669,7 +673,14 @@ jobs:
       # Filter out GB300 due to https://github.com/NVIDIA/cudf/issues/23498
       matrix_filter: group_by([(.ARCH), (.CUDA_VER|split(".")|map(tonumber)|.[0])]) | map(max_by([(.PY_VER|split(".")|map(tonumber)), (.CUDA_VER|split(".")|map(tonumber))])) | map(select(.GPU != "gb300" and .GPU != "gh200"))
       build_type: pull-request
-      script: ci/cudf_pandas_scripts/run_tests.sh
+      script: ci/cudf_pandas_scripts/run_tests_with_pip_cache_prototype.sh
+      cache-paths: .cache/pip
+      cache-key-prefix: pip-v1
+      cache-key-files: |
+        dependencies.yaml
+        python/cudf/pyproject.toml
+        python/libcudf/pyproject.toml
+        python/pylibcudf/pyproject.toml
   third-party-integration-tests-cudf-pandas:
     needs: [conda-python-build, conda-python-build-noarch, changed-files]
     permissions:

.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/cudf_pandas_scripts/run_tests_with_pip_cache_prototype.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+# SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+# Temporary prototype for https://github.com/rapidsai/build-planning/issues/260.
+# Download the unreleased rapids-init-pip implementation by immutable commit SHA,
+# then let the existing test script use it unchanged.
+set -eoxu pipefail
+
+GHA_TOOLS_SHA="a1aa4d1a80fcbf09da0f0b8eebf0e41ab42c0f48"
+WORKSPACE_ROOT="${GITHUB_WORKSPACE:-${PWD}}"
+GHA_TOOLS_BIN="${WORKSPACE_ROOT}/.gha-tools-prototype/bin"
+
+mkdir -p "${GHA_TOOLS_BIN}"
+curl --fail --location --silent --show-error \
+    "https://raw.githubusercontent.com/rapidsai/gha-tools/${GHA_TOOLS_SHA}/tools/rapids-init-pip" \
+    --output "${GHA_TOOLS_BIN}/rapids-init-pip"
+chmod +x "${GHA_TOOLS_BIN}/rapids-init-pip"
+export PATH="${GHA_TOOLS_BIN}:${PATH}"
+
+# Initialize the cache before reporting its state and before the test script
+# sources the same tool for its normal setup.
+source rapids-init-pip
+python -m pip cache dir
+python -m pip cache info
+
+source ci/cudf_pandas_scripts/run_tests.sh
+
+python -m pip cache info

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]