Fix LKL nightly CI: add tools/lkl build phase

.github/workflows/build-lkl.yml

@@ -1,34 +1,39 @@
 # Build prebuilt liblkl.a and publish to lkl-nightly release.
 #
-# Schedule: nightly at 03:00 UTC. Skips build if upstream LKL HEAD
-# has not changed since the last successful publish.
+# Schedule: nightly at 00:30 UTC (08:30 TST) so results land by start
+# of Taiwan workday during GitHub Actions off-peak (US evening).
+# Skips build if upstream LKL HEAD has not changed since the last
+# successful publish.
 #
 # The lkl-nightly release on sysprog21/kbox always contains exactly
 # one x86_64 and one aarch64 tarball (the latest build).
 name: Build LKL (nightly)
 
 on:
   schedule:
-    - cron: '0 3 * * *'
+    - cron: '30 0 * * *'
   workflow_dispatch:
     inputs:
       force:
         description: 'Force rebuild even if upstream is unchanged'
         type: boolean
         default: false
 
-permissions:
-  contents: write
+concurrency:
+  group: lkl-nightly
+  cancel-in-progress: false
 
 env:
   LKL_UPSTREAM: lkl/linux
-  KBOX_REPO: sysprog21/kbox
+  KBOX_REPO: ${{ github.repository }}
   NIGHTLY_TAG: lkl-nightly
 
 jobs:
   # ---- Check whether upstream LKL has new commits ----
   check-upstream:
     runs-on: ubuntu-24.04
+    permissions:
+      contents: read
     outputs:
       lkl_commit: ${{ steps.head.outputs.commit }}
       needs_build: ${{ steps.compare.outputs.needs_build }}
@@ -37,6 +42,10 @@ jobs:
         id: head
         run: |
           COMMIT=$(git ls-remote "https://github.com/${{ env.LKL_UPSTREAM }}.git" HEAD | awk '{print $1}')
+          if [ -z "$COMMIT" ]; then
+            echo "::error::Failed to resolve upstream LKL HEAD"
+            exit 1
+          fi
           echo "commit=${COMMIT}" >> "$GITHUB_OUTPUT"
           echo "Upstream LKL HEAD: ${COMMIT}"
 
@@ -45,8 +54,7 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
-          FORCE="${{ inputs.force || 'false' }}"
-          if [ "$FORCE" = "true" ]; then
+          if [ "${{ inputs.force }}" = "true" ]; then
             echo "needs_build=true" >> "$GITHUB_OUTPUT"
             echo "Forced rebuild requested."
             exit 0
@@ -68,20 +76,33 @@ jobs:
           fi
 
   # ---- Build x86_64 and aarch64 in parallel ----
-  build-x86_64:
+  build:
     needs: check-upstream
     if: needs.check-upstream.outputs.needs_build == 'true'
-    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - arch: x86_64
+            runner: ubuntu-24.04
+          - arch: aarch64
+            runner: ubuntu-24.04-arm
+    runs-on: ${{ matrix.runner }}
+    timeout-minutes: 30
     steps:
       - name: Install build dependencies
         run: |
           sudo apt-get update
           sudo apt-get install -y build-essential flex bison bc libelf-dev
 
-      - name: Clone LKL at pinned commit
+      - name: Shallow-fetch LKL at pinned commit
         run: |
-          git clone --no-checkout "https://github.com/${{ env.LKL_UPSTREAM }}.git" lkl
-          cd lkl && git checkout ${{ needs.check-upstream.outputs.lkl_commit }}
+          git init lkl && cd lkl
+          git remote add origin "https://github.com/${{ env.LKL_UPSTREAM }}.git"
+          git fetch --depth=1 origin ${{ needs.check-upstream.outputs.lkl_commit }}
+          git checkout FETCH_HEAD
 
       - name: Configure LKL
         working-directory: lkl
@@ -107,86 +128,13 @@ jobs:
           ./scripts/config --disable CONFIG_CIFS
           make ARCH=lkl olddefconfig
 
-      - name: Build LKL
+      - name: Build LKL kernel
         working-directory: lkl
         run: make ARCH=lkl -j$(nproc)
 
-      - name: Verify symbols
-        working-directory: lkl
-        run: |
-          test -f tools/lkl/liblkl.a || { echo "liblkl.a not found"; exit 1; }
-          for sym in lkl_init lkl_start_kernel lkl_cleanup lkl_syscall \
-                     lkl_strerror lkl_disk_add lkl_mount_dev \
-                     lkl_host_ops lkl_dev_blk_ops; do
-            if ! nm tools/lkl/liblkl.a 2>/dev/null | awk -v s="$sym" \
-                '$3 == s && $2 ~ /^[TtDdBbRr]$/ {found=1} END {exit !found}'; then
-              echo "MISSING symbol: ${sym}"; exit 1
-            fi
-          done
-
-      - name: Package
-        working-directory: lkl
-        run: |
-          mkdir -p pkg
-          cp tools/lkl/liblkl.a pkg/
-          cp tools/lkl/include/lkl.h pkg/ 2>/dev/null || true
-          cp tools/lkl/include/lkl/autoconf.h pkg/ 2>/dev/null || true
-          cp scripts/gdb/vmlinux-gdb.py pkg/ 2>/dev/null || true
-          echo "commit=$(git rev-parse HEAD)" > pkg/BUILD_INFO
-          echo "date=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> pkg/BUILD_INFO
-          echo "arch=x86_64" >> pkg/BUILD_INFO
-          cd pkg && sha256sum ./* > sha256sums.txt
-          cd .. && tar czf liblkl-x86_64.tar.gz -C pkg .
-
-      - name: Upload artifact
-        uses: actions/upload-artifact@v7
-        with:
-          name: lkl-x86_64
-          path: lkl/liblkl-x86_64.tar.gz
-          retention-days: 3
-
-  build-aarch64:
-    needs: check-upstream
-    if: needs.check-upstream.outputs.needs_build == 'true'
-    runs-on: ubuntu-24.04-arm
-    steps:
-      - name: Install build dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y build-essential flex bison bc libelf-dev
-
-      - name: Clone LKL at pinned commit
-        run: |
-          git clone --no-checkout "https://github.com/${{ env.LKL_UPSTREAM }}.git" lkl
-          cd lkl && git checkout ${{ needs.check-upstream.outputs.lkl_commit }}
-
-      - name: Configure LKL
+      - name: Build liblkl.a
         working-directory: lkl
-        run: |
-          make ARCH=lkl defconfig
-          ./scripts/config --enable CONFIG_DEVTMPFS
-          ./scripts/config --enable CONFIG_DEVTMPFS_MOUNT
-          ./scripts/config --enable CONFIG_DEVPTS_FS
-          ./scripts/config --enable CONFIG_DEBUG_INFO
-          ./scripts/config --set-val CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT y
-          ./scripts/config --enable CONFIG_GDB_SCRIPTS
-          ./scripts/config --enable CONFIG_SCHED_DEBUG
-          ./scripts/config --enable CONFIG_PROC_SYSCTL
-          ./scripts/config --enable CONFIG_PRINTK
-          ./scripts/config --enable CONFIG_TRACEPOINTS
-          ./scripts/config --enable CONFIG_FTRACE
-          ./scripts/config --enable CONFIG_DEBUG_FS
-          ./scripts/config --disable CONFIG_MODULES
-          ./scripts/config --disable CONFIG_SOUND
-          ./scripts/config --disable CONFIG_USB_SUPPORT
-          ./scripts/config --disable CONFIG_INPUT
-          ./scripts/config --disable CONFIG_NFS_FS
-          ./scripts/config --disable CONFIG_CIFS
-          make ARCH=lkl olddefconfig
-
-      - name: Build LKL
-        working-directory: lkl
-        run: make ARCH=lkl -j$(nproc)
+        run: make -C tools/lkl -j$(nproc)
 
       - name: Verify symbols
         working-directory: lkl
@@ -211,38 +159,32 @@ jobs:
           cp scripts/gdb/vmlinux-gdb.py pkg/ 2>/dev/null || true
           echo "commit=$(git rev-parse HEAD)" > pkg/BUILD_INFO
           echo "date=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> pkg/BUILD_INFO
-          echo "arch=aarch64" >> pkg/BUILD_INFO
+          echo "arch=${{ matrix.arch }}" >> pkg/BUILD_INFO
           cd pkg && sha256sum ./* > sha256sums.txt
-          cd .. && tar czf liblkl-aarch64.tar.gz -C pkg .
+          cd .. && tar czf liblkl-${{ matrix.arch }}.tar.gz -C pkg .
 
       - name: Upload artifact
         uses: actions/upload-artifact@v7
         with:
-          name: lkl-aarch64
-          path: lkl/liblkl-aarch64.tar.gz
+          name: lkl-${{ matrix.arch }}
+          path: lkl/liblkl-${{ matrix.arch }}.tar.gz
           retention-days: 3
 
   # ---- Publish: replace lkl-nightly release with latest artifacts ----
   publish-nightly:
-    needs: [check-upstream, build-x86_64, build-aarch64]
+    needs: [check-upstream, build]
     if: needs.check-upstream.outputs.needs_build == 'true'
     runs-on: ubuntu-24.04
+    permissions:
+      contents: write
     steps:
       - name: Download artifacts
         uses: actions/download-artifact@v8
         with:
           path: dist/
           merge-multiple: true
 
-      - name: Delete old nightly release (if exists)
-        env:
-          GH_TOKEN: ${{ github.token }}
-        run: |
-          gh release delete "${{ env.NIGHTLY_TAG }}" \
-            --repo "${{ env.KBOX_REPO }}" \
-            --yes --cleanup-tag 2>/dev/null || true
-
-      - name: Create nightly release
+      - name: Publish nightly release
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
@@ -261,6 +203,12 @@ jobs:
           BUILD_INFO, sha256sums.txt
           EOF
 
+          # Delete-then-create is atomic enough: both build jobs succeeded,
+          # and the concurrency group prevents overlapping runs.
+          gh release delete "${{ env.NIGHTLY_TAG }}" \
+            --repo "${{ env.KBOX_REPO }}" \
+            --yes --cleanup-tag 2>/dev/null || true
+
           gh release create "${{ env.NIGHTLY_TAG }}" \
             --repo "${{ env.KBOX_REPO }}" \
             --title "LKL nightly (${BUILD_DATE})" \