diff --git a/.github/workflows/build_cc.yml b/.github/workflows/build_cc.yml
index 71db83fff9..ba9f581dca 100644
--- a/.github/workflows/build_cc.yml
+++ b/.github/workflows/build_cc.yml
@@ -15,6 +15,15 @@ jobs:
   buildcc:
     name: Build C++
     runs-on: ubuntu-22.04
+    env:
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+      CCACHE_BASEDIR: ${{ github.workspace }}
+      CCACHE_COMPILERCHECK: content
+      CCACHE_MAXSIZE: 1G
+      CCACHE_COMPRESS: "true"
+      CCACHE_VERSION: "4.14"
+      LAMMPS_VERSION: stable_22Jul2025_update2
+      LAMMPS_SOURCE_DIR: ${{ github.workspace }}/.cache/lammps/stable_22Jul2025_update2
     strategy:
       matrix:
         include:
@@ -49,12 +58,52 @@ jobs:
           && sudo apt-get update \
           && sudo apt-get install -y rocm-dev hipcub-dev
         if: matrix.variant == 'rocm'
+      - name: Restore LAMMPS source
+        id: lammps-cache
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: ${{ env.LAMMPS_SOURCE_DIR }}
+          key: lammps-source-${{ env.LAMMPS_VERSION }}-v1
+      - name: Fetch LAMMPS source
+        if: steps.lammps-cache.outputs.cache-hit != 'true'
+        shell: bash
+        run: |
+          rm -rf "$LAMMPS_SOURCE_DIR"
+          git clone --depth 1 --branch "$LAMMPS_VERSION" \
+            https://github.com/lammps/lammps "$LAMMPS_SOURCE_DIR"
+      - name: Install ccache
+        shell: bash
+        run: |
+          CCACHE_ARCHIVE="ccache-${CCACHE_VERSION}-linux-x86_64-musl-static.tar.xz"
+          curl -L --fail --retry 3 \
+            "https://github.com/ccache/ccache/releases/download/v${CCACHE_VERSION}/${CCACHE_ARCHIVE}" \
+            -o "$RUNNER_TEMP/$CCACHE_ARCHIVE"
+          echo "888eaf9697919d6eba77be797e9d9c9e40e734d11d67d25a79b075c3f79f6c77  $RUNNER_TEMP/$CCACHE_ARCHIVE" | sha256sum -c -
+          tar -xJf "$RUNNER_TEMP/$CCACHE_ARCHIVE" -C "$RUNNER_TEMP"
+          echo "$RUNNER_TEMP/ccache-${CCACHE_VERSION}-linux-x86_64-musl-static" >> "$GITHUB_PATH"
+      - name: Restore ccache
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: ${{ env.CCACHE_DIR }}
+          key: ccache-build-cc-${{ matrix.variant }}-v${{ env.CCACHE_VERSION }}-${{ github.run_id }}-${{ github.run_attempt }}
+          restore-keys: |
+            ccache-build-cc-${{ matrix.variant }}-v${{ env.CCACHE_VERSION }}-
+      - name: Reset ccache statistics
+        run: |
+          ccache --version
+          ccache --zero-stats
       - run: |
           source/install/build_cc.sh
         env:
           DP_VARIANT: ${{ matrix.dp_variant }}
           DOWNLOAD_TENSORFLOW: "FALSE"
           CMAKE_GENERATOR: Ninja
+          CMAKE_ARGS: "-DCMAKE_DISABLE_PRECOMPILE_HEADERS=ON"
+          LAMMPS_SOURCE_ROOT: ${{ env.LAMMPS_SOURCE_DIR }}
+          CMAKE_C_COMPILER_LAUNCHER: ccache
+          CMAKE_CXX_COMPILER_LAUNCHER: ccache
+          CMAKE_CUDA_COMPILER_LAUNCHER: ccache
+          CMAKE_HIP_COMPILER_LAUNCHER: ccache
         if: matrix.variant != 'clang'
       - run: |
           source/install/build_cc.sh
@@ -64,7 +113,14 @@ jobs:
           CC: clang
           CXX: clang++
           CMAKE_GENERATOR: Ninja
+          CMAKE_ARGS: "-DCMAKE_DISABLE_PRECOMPILE_HEADERS=ON"
+          LAMMPS_SOURCE_ROOT: ${{ env.LAMMPS_SOURCE_DIR }}
+          CMAKE_C_COMPILER_LAUNCHER: ccache
+          CMAKE_CXX_COMPILER_LAUNCHER: ccache
         if: matrix.variant == 'clang'
+      - name: Show ccache statistics
+        if: always()
+        run: ccache --show-stats
       - name: Test files exist
         run: |
           test -f dp/bin/dp_ipi &&
diff --git a/doc/conf.py b/doc/conf.py
index 5753b2afed..78b3bc2a85 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -142,6 +142,10 @@
 # This pattern also affects html_static_path and html_extra_path.
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
+# External inventories are optional cross-reference metadata. Limit connection
+# and read-inactivity waits so Sphinx can warn and continue if a host stalls.
+# This is not a deadline for the full download or documentation build.
+intersphinx_timeout = 30
 intersphinx_mapping = {
     "numpy": ("https://docs.scipy.org/doc/numpy/", None),
     "python": ("https://docs.python.org/", None),
diff --git a/source/api_cc/src/DataModifierTF.cc b/source/api_cc/src/DataModifierTF.cc
index bce80f9606..d35f365ef4 100644
--- a/source/api_cc/src/DataModifierTF.cc
+++ b/source/api_cc/src/DataModifierTF.cc
@@ -3,6 +3,7 @@
 #include "DataModifierTF.h"
 
 #include "common.h"
+#include "device.h"
 
 using namespace deepmd;
 using namespace tensorflow;
diff --git a/source/api_cc/src/DeepTensorTF.cc b/source/api_cc/src/DeepTensorTF.cc
index 12bfc15eaf..bc7c191974 100644
--- a/source/api_cc/src/DeepTensorTF.cc
+++ b/source/api_cc/src/DeepTensorTF.cc
@@ -2,6 +2,8 @@
 #ifdef BUILD_TENSORFLOW
 #include "DeepTensorTF.h"
 
+#include "device.h"
+
 using namespace deepmd;
 using namespace tensorflow;
 
diff --git a/source/install/build_cc.sh b/source/install/build_cc.sh
index 56c50e92f5..3cd499d137 100755
--- a/source/install/build_cc.sh
+++ b/source/install/build_cc.sh
@@ -5,6 +5,11 @@ if [ "$DP_VARIANT" = "cuda" ]; then
 elif [ "$DP_VARIANT" = "rocm" ]; then
 	CUDA_ARGS="-DUSE_ROCM_TOOLKIT=TRUE"
 fi
+if [ -n "${LAMMPS_SOURCE_ROOT:-}" ]; then
+	LAMMPS_ARGS="-D LAMMPS_SOURCE_ROOT=${LAMMPS_SOURCE_ROOT}"
+else
+	LAMMPS_ARGS="-D LAMMPS_VERSION=stable_22Jul2025_update2"
+fi
 #------------------
 
 SCRIPT_PATH=$(dirname $(realpath -s $0))
@@ -26,7 +31,8 @@ cmake -D ENABLE_TENSORFLOW=ON \
 	-D USE_TF_PYTHON_LIBS=TRUE \
 	-D USE_PT_PYTHON_LIBS=TRUE \
 	${CUDA_ARGS} \
-	-D LAMMPS_VERSION=stable_22Jul2025_update2 \
+	${LAMMPS_ARGS} \
+	${CMAKE_ARGS:-} \
 	..
 cmake --build . -j${NPROC}
 cmake --install .