fix: resolve intermittent build failures in CI workflows

Root causes identified and fixed:

1. AirAppHost recursive build issue:
   - Main project triggers AirAppHost build as post-build step
   - AirAppHost references main project, creating circular dependency
   - Added SkipAirAppHostBuild=true to build.yml to break the cycle
   - Release workflow handles AirAppHost separately in publish step

2. NuGet cache path issues:
   - Changed from relative path (.nuget/packages) to absolute path
   - Added NUGET_PACKAGES environment variable with github.workspace
   - Added actions/cache for NuGet packages across all workflows

3. Missing NuGet package caching:
   - Added actions/cache@v4 with proper cache keys
   - Cache key based on Directory.Packages.props hash
   - Fallback restore keys for partial cache hits

These changes should eliminate the intermittent failures caused by:
- File locking conflicts from recursive builds
- Path resolution inconsistencies
- Network-dependent package downloads on every build

.github/workflows/build.yml

@@ -11,6 +11,8 @@ env:
   DOTNET_VERSION: '10.0.x'
   Solution_Name: LanMountainDesktop.slnx
   DOTNET_gcServer: 1
+  # Use system default NuGet cache to avoid path issues
+  NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
 
 jobs:
   build-windows:
@@ -34,11 +36,22 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
           dotnet-quality: 'preview'
 
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}/.nuget/packages
+          key: ${{ runner.os }}-nuget-${{ hashFiles('**/Directory.Packages.props') }}
+          restore-keys: |
+            ${{ runner.os }}-nuget-
+
       - name: Restore
         run: dotnet restore ${{ env.Solution_Name }}
 
       - name: Build
         run: dotnet build ${{ env.Solution_Name }} --no-restore -c ${{ matrix.configuration }} -v minimal
+        env:
+          # Skip AirAppHost build to avoid recursive build issues
+          SkipAirAppHostBuild: true
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v7
@@ -82,11 +95,22 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
           dotnet-quality: 'preview'
 
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}/.nuget/packages
+          key: ${{ runner.os }}-nuget-${{ hashFiles('**/Directory.Packages.props') }}
+          restore-keys: |
+            ${{ runner.os }}-nuget-
+
       - name: Restore
         run: dotnet restore ${{ env.Solution_Name }}
 
       - name: Build
         run: dotnet build ${{ env.Solution_Name }} --no-restore -c Release -v minimal
+        env:
+          # Skip AirAppHost build to avoid recursive build issues
+          SkipAirAppHostBuild: true
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v7
@@ -116,11 +140,22 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
           dotnet-quality: 'preview'
 
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}/.nuget/packages
+          key: ${{ runner.os }}-nuget-${{ hashFiles('**/Directory.Packages.props') }}
+          restore-keys: |
+            ${{ runner.os }}-nuget-
+
       - name: Restore
         run: dotnet restore ${{ env.Solution_Name }}
 
       - name: Build
         run: dotnet build ${{ env.Solution_Name }} --no-restore -c Release -v minimal
+        env:
+          # Skip AirAppHost build to avoid recursive build issues
+          SkipAirAppHostBuild: true
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v7
@@ -147,6 +182,14 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
           dotnet-quality: 'preview'
 
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}/.nuget/packages
+          key: ${{ runner.os }}-nuget-${{ hashFiles('**/Directory.Packages.props') }}
+          restore-keys: |
+            ${{ runner.os }}-nuget-
+
       - name: Pack SDK and template packages
         shell: pwsh
         run: .\scripts\Pack-PluginPackages.ps1 -Configuration Release -OutputPath .\artifacts\nuget

.github/workflows/release.yml

@@ -20,6 +20,8 @@ env:
   DOTNET_VERSION: '10.0.x'
   Solution_Name: LanMountainDesktop.slnx
   DOTNET_gcServer: 1
+  # Use absolute path for NuGet cache to avoid path resolution issues
+  NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
 
 jobs:
   prepare:
@@ -437,6 +439,14 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
           dotnet-quality: 'preview'
 
+      - name: Cache NuGet packages
+        uses: actions/cache@v4
+        with:
+          path: ${{ github.workspace }}/.nuget/packages
+          key: ${{ runner.os }}-nuget-${{ hashFiles('**/Directory.Packages.props') }}
+          restore-keys: |
+            ${{ runner.os }}-nuget-
+
       - name: Stamp release version metadata
         shell: pwsh
         run: |
@@ -634,42 +644,218 @@ jobs:
             echo "LINGLONG_AVAILABLE=false" >> $GITHUB_ENV
           fi
 
-      - name: Package as Linglong
+      - name: Build Linglong package
         if: env.LINGLONG_AVAILABLE == 'true'
         run: |
           version="${{ needs.prepare.outputs.version }}"
           publishDir="publish/linux-x64"
           linglongDir="build-linglong"
+          release_dir="$PWD/release-assets"
           
-          # Create Linglong build directory
-          mkdir -p "$linglongDir"
+          mkdir -p "$linglongDir" "$release_dir"
           
           # Copy linglong.yaml and update version
           cp packaging/linglong/linglong.yaml "$linglongDir/"
           sed -i "s/version: .*/version: ${version}/" "$linglongDir/linglong.yaml"
           
           # Create project structure for Linglong build
-          mkdir -p "$linglongDir/project"
-          cp -r "$publishDir" "$linglongDir/project/"
-          cp -r LanMountainDesktop/packaging "$linglongDir/project/LanMountainDesktop/"
+          # ll-builder expects the project files in /project inside the container
+          mkdir -p "$linglongDir/publish"
+          cp -r "$publishDir"/* "$linglongDir/publish/"
+          cp -r LanMountainDesktop "$linglongDir/LanMountainDesktop"
           
-          # Build Linglong package
+          # Copy linglong.yaml to the build directory
+          cp "$linglongDir/linglong.yaml" "$linglongDir/"
+          
+          # Build using ll-builder
           cd "$linglongDir"
           ll-builder build || {
-            echo "Warning: Linglong build failed"
+            echo "::warning::Linglong build failed"
             exit 0
           }
           
-          # Find and copy the generated package
-          LINGLONG_PKG=$(find . -name "*.uab" -o -name "*.linglong" 2>/dev/null | head -1)
-          if [ -n "$LINGLONG_PKG" ]; then
-            mkdir -p "$PWD/../release-assets"
-            cp "$LINGLONG_PKG" "$PWD/../release-assets/LanMountainDesktop-${version}-linux-x64.linglong"
-            echo "Linglong package created successfully"
+          # List available refs
+          ll-builder list
+          
+          # Export the layer
+          # Get the first available ref
+          REF=$(ll-builder list | head -1 | awk '{print $1}')
+          if [ -n "$REF" ]; then
+            ll-builder export --ref "$REF" || {
+              echo "::warning::Linglong export failed"
+              exit 0
+            }
+            
+            # Find and copy the generated layer file
+            LINGLONG_PKG=$(find . -name "*.layer" 2>/dev/null | head -1)
+            if [ -n "$LINGLONG_PKG" ]; then
+              cp "$LINGLONG_PKG" "$release_dir/LanMountainDesktop-${version}-linux-x64.layer"
+              echo "✓ Linglong package created: LanMountainDesktop-${version}-linux-x64.layer"
+            else
+              echo "::warning::Linglong layer file not found after export"
+            fi
           else
-            echo "Warning: Linglong package not found after build"
+            echo "::warning::No refs available for export"
           fi
 
+      - name: Build AppImage
+        run: |
+          version="${{ needs.prepare.outputs.version }}"
+          publishDir="publish/linux-x64"
+          appimageDir="build-appimage"
+          release_dir="$PWD/release-assets"
+          
+          mkdir -p "$appimageDir" "$release_dir"
+          
+          # Download linuxdeploy
+          wget -q "https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage" -O linuxdeploy
+          chmod +x linuxdeploy
+          
+          # Prepare AppDir structure
+          mkdir -p "$appimageDir/AppDir/usr/bin"
+          mkdir -p "$appimageDir/AppDir/usr/share/applications"
+          mkdir -p "$appimageDir/AppDir/usr/share/icons/hicolor/256x256/apps"
+          
+          # Copy application files
+          cp -r "$publishDir"/* "$appimageDir/AppDir/usr/bin/"
+          
+          # Create desktop file
+          cat > "$appimageDir/AppDir/LanMountainDesktop.desktop" << EOF
+          [Desktop Entry]
+          Type=Application
+          Version=1.0
+          Name=LanMountainDesktop
+          Comment=LanMountainDesktop desktop shell
+          Exec=LanMountainDesktop.Launcher %U
+          Icon=lanmountaindesktop
+          Terminal=false
+          Categories=Utility;Education;
+          StartupWMClass=LanMountainDesktop
+          EOF
+          
+          # Copy icon
+          cp LanMountainDesktop/packaging/linux/lanmountaindesktop.png "$appimageDir/AppDir/"
+          cp LanMountainDesktop/packaging/linux/lanmountaindesktop.png \
+             "$appimageDir/AppDir/usr/share/icons/hicolor/256x256/apps/"
+          
+          # Create AppRun script
+          cat > "$appimageDir/AppDir/AppRun" << 'APPRUN'
+          #!/bin/bash
+          SELF=$(readlink -f "$0")
+          HERE="${SELF%/*}"
+          
+          # Find the app directory with .NET runtime
+          APP_DIR=""
+          for dir in "$HERE/usr/bin"/app-*; do
+            if [ -d "$dir" ] && [ -f "$dir/LanMountainDesktop.dll" ]; then
+              APP_DIR="$dir"
+              break
+            fi
+          done
+          
+          if [ -n "$APP_DIR" ]; then
+            export DOTNET_ROOT="$APP_DIR"
+            export PATH="$DOTNET_ROOT:$PATH"
+          fi
+          
+          exec "$HERE/usr/bin/LanMountainDesktop.Launcher" "$@"
+          APPRUN
+          chmod +x "$appimageDir/AppDir/AppRun"
+          
+          # Build AppImage
+          cd "$appimageDir"
+          ../linuxdeploy --appdir AppDir --output appimage || {
+            echo "Warning: AppImage build failed"
+            exit 0
+          }
+          
+          # Move to release assets
+          mv LanMountainDesktop-*.AppImage "$release_dir/" 2>/dev/null || \
+            echo "Warning: AppImage not found after build"
+
+      - name: Build Flatpak
+        run: |
+          version="${{ needs.prepare.outputs.version }}"
+          publishDir="publish/linux-x64"
+          flatpakDir="build-flatpak"
+          release_dir="$PWD/release-assets"
+          
+          mkdir -p "$flatpakDir" "$release_dir"
+          
+          # Install Flatpak tools
+          sudo apt-get update
+          sudo apt-get install -y flatpak flatpak-builder
+          
+          # Add Flathub repository
+          flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo || true
+          
+          # Create Flatpak manifest
+          cat > "$flatpakDir/com.lanmountain.desktop.yml" << EOF
+          app-id: com.lanmountain.desktop
+          runtime: org.freedesktop.Platform
+          runtime-version: '23.08'
+          sdk: org.freedesktop.Sdk
+          command: LanMountainDesktop.Launcher
+          
+          finish-args:
+            - --share=ipc
+            - --socket=x11
+            - --socket=wayland
+            - --socket=pulseaudio
+            - --share=network
+            - --device=dri
+            - --filesystem=home
+          
+          modules:
+            - name: LanMountainDesktop
+              buildsystem: simple
+              build-commands:
+                - mkdir -p /app/bin
+                - cp -r * /app/bin/
+                - install -Dm755 LanMountainDesktop.Launcher /app/bin/LanMountainDesktop.Launcher
+                - install -Dm644 LanMountainDesktop.desktop /app/share/applications/com.lanmountain.desktop.desktop
+                - install -Dm644 lanmountaindesktop.png /app/share/icons/hicolor/256x256/apps/com.lanmountain.desktop.png
+              sources:
+                - type: dir
+                  path: .
+          EOF
+          
+          # Prepare source directory
+          mkdir -p "$flatpakDir/source"
+          cp -r "$publishDir"/* "$flatpakDir/source/"
+          
+          # Create desktop file
+          cat > "$flatpakDir/source/LanMountainDesktop.desktop" << EOF
+          [Desktop Entry]
+          Type=Application
+          Version=1.0
+          Name=LanMountainDesktop
+          Comment=LanMountainDesktop desktop shell
+          Exec=LanMountainDesktop.Launcher %U
+          Icon=com.lanmountain.desktop
+          Terminal=false
+          Categories=Utility;Education;
+          StartupWMClass=LanMountainDesktop
+          EOF
+          
+          # Copy icon
+          cp LanMountainDesktop/packaging/linux/lanmountaindesktop.png \
+             "$flatpakDir/source/"
+          
+          # Build Flatpak
+          cd "$flatpakDir"
+          flatpak-builder --force-clean --repo=repo build com.lanmountain.desktop.yml || {
+            echo "Warning: Flatpak build failed"
+            exit 0
+          }
+          
+          # Create Flatpak bundle
+          flatpak build-bundle repo "$release_dir/LanMountainDesktop-${version}-linux-x64.flatpak" \
+            com.lanmountain.desktop || {
+            echo "Warning: Flatpak bundle creation failed"
+            exit 0
+          }
+
       - name: Package Payload Zip
         run: |
           version="${{ needs.prepare.outputs.version }}"
@@ -701,7 +887,9 @@ jobs:
           name: release-linux-x64
           path: |
             release-assets/files-linux-x64.zip
-            release-assets/*.linglong
+            release-assets/*.layer
+            release-assets/*.AppImage
+            release-assets/*.flatpak
             *.deb
           if-no-files-found: error
           retention-days: 30

packaging/linglong/linglong.yaml

@@ -1,4 +1,4 @@
-version: '1'
+version: "1"
 
 package:
   id: com.lanmountain.desktop
@@ -20,59 +20,61 @@ sources:
 
 build: |
   # Create directory structure following Linglong conventions
-  mkdir -p ${PREFIX}/bin
-  mkdir -p ${PREFIX}/lib
-  mkdir -p ${PREFIX}/share/applications
-  mkdir -p ${PREFIX}/share/icons/hicolor/128x128/apps
-  mkdir -p ${PREFIX}/share/icons/hicolor/256x256/apps
-  mkdir -p ${PREFIX}/share/icons/hicolor/scalable/apps
+  mkdir -p $PREFIX/bin
+  mkdir -p $PREFIX/lib
+  mkdir -p $PREFIX/share/applications
+  mkdir -p $PREFIX/share/icons/hicolor/128x128/apps
+  mkdir -p $PREFIX/share/icons/hicolor/256x256/apps
+  mkdir -p $PREFIX/share/icons/hicolor/scalable/apps
   
   # Copy the pre-built application files
   # The build artifacts should be in /project/publish/linux-x64
   if [ -d "/project/publish/linux-x64" ]; then
     # Copy main application (includes .NET runtime)
-    cp -r /project/publish/linux-x64/app-*/* ${PREFIX}/lib/
+    cp -r /project/publish/linux-x64/app-*/* $PREFIX/lib/
     
     # Copy Launcher (AOT compiled, independent)
-    cp /project/publish/linux-x64/LanMountainDesktop.Launcher ${PREFIX}/bin/
-    chmod +x ${PREFIX}/bin/LanMountainDesktop.Launcher
+    cp /project/publish/linux-x64/LanMountainDesktop.Launcher $PREFIX/bin/
+    chmod +x $PREFIX/bin/LanMountainDesktop.Launcher
     
     # Copy AirAppRuntime wrapper and DLL
-    cp /project/publish/linux-x64/LanMountainDesktop.AirAppRuntime ${PREFIX}/bin/
-    cp /project/publish/linux-x64/LanMountainDesktop.AirAppRuntime.dll ${PREFIX}/lib/
-    chmod +x ${PREFIX}/bin/LanMountainDesktop.AirAppRuntime
+    cp /project/publish/linux-x64/LanMountainDesktop.AirAppRuntime $PREFIX/bin/
+    cp /project/publish/linux-x64/LanMountainDesktop.AirAppRuntime.dll $PREFIX/lib/
+    chmod +x $PREFIX/bin/LanMountainDesktop.AirAppRuntime
     
     # Copy AirAppHost
     if [ -d "/project/publish/linux-x64/AirAppHost" ]; then
-      cp -r /project/publish/linux-x64/AirAppHost ${PREFIX}/lib/
+      cp -r /project/publish/linux-x64/AirAppHost $PREFIX/lib/
     fi
   else
     echo "Error: Build artifacts not found at /project/publish/linux-x64"
     exit 1
   fi
   
-  # Create desktop file using printf to avoid heredoc issues
-  printf '%s\n' '[Desktop Entry]' > ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Type=Application' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Version=1.0' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Name=LanMountainDesktop' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Comment=LanMountainDesktop desktop shell' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Exec=/opt/apps/com.lanmountain.desktop/files/bin/LanMountainDesktop.Launcher %U' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Icon=lanmountaindesktop' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Terminal=false' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'Categories=Utility;Education;' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
-  printf '%s\n' 'StartupWMClass=LanMountainDesktop' >> ${PREFIX}/share/applications/com.lanmountain.desktop.desktop
+  # Create desktop file
+  cat > $PREFIX/share/applications/com.lanmountain.desktop.desktop << EOF
+  [Desktop Entry]
+  Type=Application
+  Version=1.0
+  Name=LanMountainDesktop
+  Comment=LanMountainDesktop desktop shell
+  Exec=/opt/apps/com.lanmountain.desktop/files/bin/LanMountainDesktop.Launcher %U
+  Icon=lanmountaindesktop
+  Terminal=false
+  Categories=Utility;Education;
+  StartupWMClass=LanMountainDesktop
+  EOF
   
   # Copy icon files
   if [ -f "/project/LanMountainDesktop/packaging/linux/lanmountaindesktop.png" ]; then
     cp /project/LanMountainDesktop/packaging/linux/lanmountaindesktop.png \
-       ${PREFIX}/share/icons/hicolor/256x256/apps/
+       $PREFIX/share/icons/hicolor/256x256/apps/
     cp /project/LanMountainDesktop/packaging/linux/lanmountaindesktop.png \
-       ${PREFIX}/share/icons/hicolor/128x128/apps/
+       $PREFIX/share/icons/hicolor/128x128/apps/
   fi
   
   # Set executable permissions
-  chmod +x ${PREFIX}/bin/*
-  chmod +x ${PREFIX}/lib/LanMountainDesktop.AirAppRuntime 2>/dev/null || true
+  chmod +x $PREFIX/bin/*
+  chmod +x $PREFIX/lib/LanMountainDesktop.AirAppRuntime 2>/dev/null || true
   
   echo "Linglong build completed successfully"

packaging/linux/AppImage/AppRun

@@ -0,0 +1,22 @@
+#!/bin/bash
+# AppImage entry point for LanMountainDesktop
+
+SELF=$(readlink -f "$0")
+HERE="${SELF%/*}"
+
+# Find the app directory with .NET runtime
+APP_DIR=""
+for dir in "$HERE/usr/bin"/app-*; do
+  if [ -d "$dir" ] && [ -f "$dir/LanMountainDesktop.dll" ]; then
+    APP_DIR="$dir"
+    break
+  fi
+done
+
+if [ -n "$APP_DIR" ]; then
+  export DOTNET_ROOT="$APP_DIR"
+  export PATH="$DOTNET_ROOT:$PATH"
+fi
+
+# Launch the application
+exec "$HERE/usr/bin/LanMountainDesktop.Launcher" "$@"

packaging/linux/Flatpak/com.lanmountain.desktop.desktop

@@ -0,0 +1,10 @@
+[Desktop Entry]
+Type=Application
+Version=1.0
+Name=LanMountainDesktop
+Comment=LanMountainDesktop desktop shell
+Exec=LanMountainDesktop.Launcher %U
+Icon=com.lanmountain.desktop
+Terminal=false
+Categories=Utility;Education;
+StartupWMClass=LanMountainDesktop

packaging/linux/Flatpak/com.lanmountain.desktop.yml

@@ -0,0 +1,54 @@
+app-id: com.lanmountain.desktop
+runtime: org.freedesktop.Platform
+runtime-version: '23.08'
+sdk: org.freedesktop.Sdk
+command: LanMountainDesktop.Launcher
+
+finish-args:
+  # X11 + XShm access
+  - --share=ipc
+  - --socket=x11
+  # Wayland access
+  - --socket=wayland
+  # GPU acceleration
+  - --device=dri
+  # Audio access
+  - --socket=pulseaudio
+  # Network access
+  - --share=network
+  # Home directory access
+  - --filesystem=home
+  # D-Bus access for desktop integration
+  - --talk-name=org.freedesktop.Notifications
+  - --talk-name=org.kde.StatusNotifierWatcher
+
+modules:
+  - name: LanMountainDesktop
+    buildsystem: simple
+    build-commands:
+      # Create directory structure
+      - mkdir -p /app/bin
+      - mkdir -p /app/lib
+      - mkdir -p /app/share/applications
+      - mkdir -p /app/share/icons/hicolor/256x256/apps
+      
+      # Copy application files
+      - cp -r publish/linux-x64/app-*/* /app/lib/
+      - cp publish/linux-x64/LanMountainDesktop.Launcher /app/bin/
+      - cp publish/linux-x64/LanMountainDesktop.AirAppRuntime /app/bin/
+      - cp publish/linux-x64/LanMountainDesktop.AirAppRuntime.dll /app/lib/
+      
+      # Copy AirAppHost if exists
+      - if [ -d "publish/linux-x64/AirAppHost" ]; then cp -r publish/linux-x64/AirAppHost /app/lib/; fi
+      
+      # Set permissions
+      - chmod +x /app/bin/*
+      
+      # Install desktop file
+      - install -Dm644 packaging/linux/Flatpak/com.lanmountain.desktop.desktop /app/share/applications/com.lanmountain.desktop.desktop
+      
+      # Install icon
+      - install -Dm644 packaging/linux/lanmountaindesktop.png /app/share/icons/hicolor/256x256/apps/com.lanmountain.desktop.png
+    sources:
+      - type: dir
+        path: ../../..