build: Disable step "Cache toolchain" and fix host dir

.github/workflows/build.yml

@@ -259,25 +259,58 @@ jobs:
       - name: Prepare for use cache of tools and toolchain
         run: |
           echo "G_TARGET_ARCH = $G_TARGET_ARCH"
-          rm -rf staging_dir/
-          rm -rf build_dir/
-
+          mkdir -p staging_dir/host
+          rm -rf /tmp/staging-host
+          mkdir -p /tmp/staging-host
+          cp -a staging_dir/host/* /tmp/staging-host/
+          rm -rf staging_dir/host/*
+    
       - name: Cache host tools
         uses: actions/cache@v4
         with:
           path: staging_dir/host
           key: host-tools-${{ runner.os }}-${{ hashFiles('tools/**') }}
+          save-always: true
           restore-keys: |
             host-tools-${{ runner.os }}-
 
       - name: Cache toolchain
+        if: false
         uses: actions/cache@v4
         with:
           path: staging_dir/toolchain-*
           key: toolchain-${{ env.G_TARGET_ARCH }}-${{ hashFiles('toolchain/**') }}
+          save-always: true
           restore-keys: |
             toolchain-${{ env.G_TARGET_ARCH }}-
 
+      - name: Restore saved host staging
+        run: |
+          cp -af /tmp/staging-host/* staging_dir/host
+          rm -rf /tmp/staging-host
+    
+      - name: Increase swap to 16G
+        if: false
+        run: |
+          free -h
+          sudo swapoff -a || true
+          sudo rm -f /swapfile
+          sudo fallocate -l 16G /swapfile
+          sudo chmod 600 /swapfile
+          sudo mkswap /swapfile
+          sudo swapon /swapfile
+    
+      - name: Monitor memory
+        run: |
+          echo "CPU cores = $(nproc)"
+          echo "Memory and swap:"
+          sudo free -h
+          echo
+          sudo swapon --show
+          echo
+          echo "Available storage:"
+          sudo df -h
+
       - name: Build tools and toolchain
         id: tools
         if: ${{ steps.configure.outputs.status == 'success' && github.event.inputs.fake_build != 'true' }}
@@ -285,20 +318,6 @@ jobs:
           make toolchain/install -j$(nproc)
           echo "status=success" >> $GITHUB_OUTPUT
 
-      - name: Save cache for host tools
-        if: ${{ steps.tools.outputs.status == 'success' && github.event.inputs.fake_build != 'true' }}
-        uses: actions/cache@v4
-        with:
-          path: staging_dir/host
-          key: host-tools-${{ runner.os }}-${{ hashFiles('tools/**') }}
-
-      - name: Save cache for toolchain
-        if: ${{ steps.tools.outputs.status == 'success' && github.event.inputs.fake_build != 'true' }}
-        uses: actions/cache@v4
-        with:
-          path: staging_dir/toolchain-*
-          key: toolchain-${{ env.G_TARGET_ARCH }}-${{ hashFiles('toolchain/**') }}
-
       - name: Kernel compile
         id: kernel
         if: ${{ steps.tools.outputs.status == 'success' && github.event.inputs.first_kernel_compile == 'true' && github.event.inputs.fake_build != 'true' }}
@@ -306,6 +325,16 @@ jobs:
           make target/linux/compile -j$(nproc)
           echo "status=success" >> $GITHUB_OUTPUT
 
+      - name: Monitor memory 2
+        run: |
+          echo "Memory and swap:"
+          sudo free -h
+          echo
+          sudo swapon --show
+          echo
+          echo "Available storage:"
+          sudo df -h
+
       - name: Build the firmware image
         id: compile
         if: steps.tools.outputs.status == 'success'
@@ -361,6 +390,13 @@ jobs:
       - name: Check space usage
         run: df -hT
 
+      - name: Check OOM error
+        if: failure()
+        run: |
+          dmesg | grep -i -E 'oom|killed process' || true
+          echo "================== Memory ================="
+          free -h
+    
       - name: Compress build logs
         if: always()
         env: