fix: handle apt showpkg warnings

- Updated variable expansions to use double quotes for better safety and to prevent word splitting.
- Replaced `ls` with `find` in cache operations to handle non-alphanumeric filenames more robustly.
- Enhanced array handling in scripts by using `${*:N}` syntax for concatenation.
- Improved readability and consistency in conditional checks by using `[[ ... ]]` instead of `[ ... ]`.
- Added comments for clarity on specific operations and shellcheck directives.

.github/workflows/action-tests.yml

@@ -0,0 +1,984 @@
+name: Action Tests
+on:
+  workflow_dispatch:
+    inputs:
+      debug:
+        description: "Run in debug mode."
+        type: boolean
+        required: false
+        default: true
+  repository_dispatch:
+  push:
+  pull_request:
+
+env:
+  DEBUG: ${{ github.event.inputs.debug || false }}
+  # Test for overrides in built in shell options (regression issue 98).
+  SHELLOPTS: errexit:pipefail
+
+jobs:
+  build_binaries:
+    uses: ./.github/workflows/build-distribute.yml
+
+  # All other jobs should depend on build_binaries (if run) or check_distribute (if not needed)
+  list_all_versions:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: List all package versions (including deps).
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot=1.3-1
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-list_all_versions
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: |
+          steps.execute.outputs.cache-hit != 'false' ||
+          steps.execute.outputs.all-package-version-list != 'fonts-liberation2=1:2.1.5-3,gir1.2-atk-1.0=2.52.0-1build1,gir1.2-freedesktop=1.80.1-1,gir1.2-gdkpixbuf-2.0=2.42.10+dfsg-3ubuntu3.2,gir1.2-gtk-3.0=3.24.41-4ubuntu1.3,gir1.2-harfbuzz-0.0=8.3.0-2build2,gir1.2-pango-1.0=1.52.1+ds-1build1,graphviz=2.42.2-9ubuntu0.1,libann0=1.1.2+doc-9build1,libblas3=3.12.0-3build1.1,libcdt5=2.42.2-9ubuntu0.1,libcgraph6=2.42.2-9ubuntu0.1,libgts-0.7-5t64=0.7.6+darcs121130-5.2build1,libgts-bin=0.7.6+darcs121130-5.2build1,libgvc6=2.42.2-9ubuntu0.1,libgvpr2=2.42.2-9ubuntu0.1,libharfbuzz-gobject0=8.3.0-2build2,liblab-gamut1=2.42.2-9ubuntu0.1,liblapack3=3.12.0-3build1.1,libpangoxft-1.0-0=1.52.1+ds-1build1,libpathplan4=2.42.2-9ubuntu0.1,python3-cairo=1.25.1-2build2,python3-gi-cairo=3.48.2-1,python3-numpy=1:1.26.4+ds-6ubuntu1,xdot=1.3-1'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          echo "package-version-list = ${{ steps.execute.outputs.package-version-list }}"
+          echo "all-package-version-list = ${{ steps.execute.outputs.all-package-version-list }}"
+          echo "diff all-package-version-list"
+          diff  <(echo "${{ steps.execute.outputs.all-package-version-list }}" ) <(echo "fonts-liberation2=1:2.1.5-3,gir1.2-atk-1.0=2.52.0-1build1,gir1.2-freedesktop=1.80.1-1,gir1.2-gdkpixbuf-2.0=2.42.10+dfsg-3ubuntu3.2,gir1.2-gtk-3.0=3.24.41-4ubuntu1.3,gir1.2-harfbuzz-0.0=8.3.0-2build2,gir1.2-pango-1.0=1.52.1+ds-1build1,graphviz=2.42.2-9ubuntu0.1,libann0=1.1.2+doc-9build1,libblas3=3.12.0-3build1.1,libcdt5=2.42.2-9ubuntu0.1,libcgraph6=2.42.2-9ubuntu0.1,libgts-0.7-5t64=0.7.6+darcs121130-5.2build1,libgts-bin=0.7.6+darcs121130-5.2build1,libgvc6=2.42.2-9ubuntu0.1,libgvpr2=2.42.2-9ubuntu0.1,libharfbuzz-gobject0=8.3.0-2build2,liblab-gamut1=2.42.2-9ubuntu0.1,liblapack3=3.12.0-3build1.1,libpangoxft-1.0-0=1.52.1+ds-1build1,libpathplan4=2.42.2-9ubuntu0.1,python3-cairo=1.25.1-2build2,python3-gi-cairo=3.48.2-1,python3-numpy=1:1.26.4+ds-6ubuntu1,xdot=1.3-1")
+          exit 1
+        shell: bash
+
+  list_versions:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: List package versions.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-list_versions
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if:
+          steps.execute.outputs.cache-hit != 'false' || steps.execute.outputs.package-version-list
+          != 'rolldice=1.16-1build3,xdot=1.3-1'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          echo "package-version-list = ${{ steps.execute.outputs.package-version-list }}"
+          echo "diff package-version-list"
+          diff  <(echo "${{ steps.execute.outputs.package-version-list }}" ) <(echo "rolldice=1.16-1build3,xdot=1.3-1")
+          exit 1
+        shell: bash
+
+  standard_workflow_install:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow install package and cache.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-standard_workflow
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'false'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  standard_workflow_install_with_new_version:
+    needs: [standard_workflow_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow packages with new version.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice
+          version:
+            ${{ github.run_id }}-${{ github.run_attempt}}-standard_workflow_install_with_new_version
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'false'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  standard_workflow_restore:
+    needs: [standard_workflow_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow restore cached packages.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-standard_workflow
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'true'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  standard_workflow_restore_with_packages_out_of_order:
+    needs: [standard_workflow_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow restore with packages out of order.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: rolldice xdot
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-standard_workflow
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'true'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  standard_workflow_add_package:
+    needs: [standard_workflow_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow add another package.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-standard_workflow
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'false'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  standard_workflow_restore_add_package:
+    needs: [standard_workflow_add_package, build_binaries]
+    runs-on: ubuntu-latest
+    name: Standard workflow restore added package.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-standard_workflow
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'true'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  no_packages:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: No packages passed.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: ""
+        continue-on-error: true
+      - name: Verify
+        if: steps.execute.outcome == 'failure'
+        run: exit 0
+        shell: bash
+
+  package_not_found:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: Package not found.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: package_that_doesnt_exist
+        continue-on-error: true
+      - name: Verify
+        if: steps.execute.outcome == 'failure'
+        run: exit 0
+        shell: bash
+
+  version_contains_spaces:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: Version contains spaces.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot
+          version: 123 abc
+          debug: ${{ env.DEBUG }}
+        continue-on-error: true
+      - name: Verify
+        if: steps.execute.outcome == 'failure'
+        run: exit 0
+        shell: bash
+
+  regression_36:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Reinstall existing package (regression issue #36)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libgtk-3-dev
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_36
+          debug: ${{ env.DEBUG }}
+
+  regression_37:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Install with reported package dependencies not installed (regression issue #37)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libosmesa6-dev libgl1-mesa-dev python3-tk pandoc git-restore-mtime
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_37
+          debug: ${{ env.DEBUG }}
+
+  debug_disabled:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: Debug disabled.
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: xdot
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-list-all-package-versions
+          debug: ${{ env.DEBUG }}
+
+  regression_72_1:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Cache Java CA certs package v1 (regression issue #72)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: openjdk-11-jre
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_72
+          debug: ${{ env.DEBUG }}
+
+  regression_72_2:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Cache Java CA certs package v2 (regression issue #72)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: default-jre
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_72
+          debug: ${{ env.DEBUG }}
+
+  regression_76:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Cache empty archive (regression issue #76)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - run: |
+          sudo wget -O- https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB | gpg --dearmor | tee /usr/share/keyrings/oneapi-archive-keyring.gpg > /dev/null;
+          echo "deb [signed-by=/usr/share/keyrings/oneapi-archive-keyring.gpg] https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list;
+          sudo apt-get -qq update;
+          sudo apt-get install -y intel-oneapi-runtime-libs intel-oneapi-runtime-opencl;
+          sudo apt-get install -y opencl-headers ocl-icd-opencl-dev;
+          sudo apt-get install -y libsundials-dev;
+      - uses: ./
+        with:
+          packages: intel-oneapi-runtime-libs
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_76
+          debug: ${{ env.DEBUG }}
+
+  regression_79:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Tar error with libboost-dev (regression issue #79)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libboost-dev
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_79
+          debug: ${{ env.DEBUG }}
+
+  regression_81:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Tar error with alsa-ucm-conf (regression issue #81)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages:
+            libasound2 libatk-bridge2.0-0 libatk1.0-0 libatspi2.0-0 libcups2 libdrm2 libgbm1
+            libnspr4 libnss3 libxcomposite1 libxdamage1 libxfixes3 libxkbcommon0 libxrandr2
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_81
+          debug: ${{ env.DEBUG }}
+
+  regression_84_literal_block_install:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Install multiline package listing using literal block style (regression issue #84)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: >
+            xdot  rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_84_literal_block
+          debug: ${{ env.DEBUG }}
+
+  regression_84_literal_block_restore:
+    needs: [regression_84_literal_block_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: "Restore multiline package listing using literal block style (regression issue #84)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_84_literal_block
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'true'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  regression_84_folded_block_install:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Install multiline package listing using literal block style (regression issue #84)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: |
+            xdot \
+            rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_84_folded_block
+          debug: ${{ env.DEBUG }}
+
+  regression_84_folded_block_restore:
+    needs: [regression_84_folded_block_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: "Restore multiline package listing using literal block style (regression issue #84)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - name: Execute
+        id: execute
+        uses: ./
+        with:
+          packages: xdot rolldice distro-info-data
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_84_folded_block
+          debug: ${{ env.DEBUG }}
+      - name: Verify
+        if: steps.execute.outputs.cache-hit != 'true'
+        run: |
+          echo "cache-hit = ${{ steps.execute.outputs.cache-hit }}"
+          exit 1
+        shell: bash
+
+  regression_89:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Upload logs artifact name (regression issue #89)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libgtk-3-dev:amd64
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_89
+          debug: ${{ env.DEBUG }}
+
+  regression_98:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Install error due to SHELLOPTS override (regression issue #98)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: git-restore-mtime libgl1-mesa-dev libosmesa6-dev pandoc
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_98
+          debug: ${{ env.DEBUG }}
+
+  regression_106_install:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Stale apt repo not finding package on restore, install phase (regression issue #106)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libtk8.6
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_106
+          debug: ${{ env.DEBUG }}
+
+  regression_106_restore:
+    needs: [regression_106_install, build_binaries]
+    runs-on: ubuntu-latest
+    name: "Stale apt repo not finding package on restore, restore phase (regression issue #106)."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libtk8.6
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-regression_106
+          debug: ${{ env.DEBUG }}
+
+  multi_arch_cache_key:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Cache packages with multi-arch cache key."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libfuse2
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-multi_arch_cache_key
+          debug: ${{ env.DEBUG }}
+
+  virtual_package:
+    needs: [build_binaries]
+    runs-on: ubuntu-latest
+    name: "Cache virtual package."
+    steps:
+      - uses: actions/checkout@v3.1.0
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: cache-apt-pkgs-*
+          path: distribute-artifacts
+      - name: Setup distribute directory
+        shell: bash
+        run: |
+          mkdir -p distribute/X64 distribute/X86 distribute/ARM64 distribute/ARM
+          for artifact_dir in distribute-artifacts/cache-apt-pkgs-*; do
+            if [ -d "$artifact_dir" ]; then
+              arch=$(basename "$artifact_dir" | sed 's/cache-apt-pkgs-\([^-]*\)-.*/\1/')
+              echo "Copying artifacts for architecture: $arch"
+              cp -r "$artifact_dir"/* "distribute/$arch/" 2>/dev/null || true
+            fi
+          done
+          ls -la distribute/*/ || true
+      - uses: ./
+        with:
+          packages: libvips
+          version: ${{ github.run_id }}-${{ github.run_attempt }}-virtual_package
+          debug: ${{ env.DEBUG }}

.github/workflows/build-distribute.yml

@@ -0,0 +1,118 @@
+name: Build and Release Distribute Artifacts
+on:
+  push:
+    tags:
+      - "v2.*.*"
+    branches:
+      - dev-v2
+  workflow_call:
+permissions:
+  contents: write
+  id-token: write
+env:
+  VERSION_PREFIX: "commit"
+  working_directory: ${{ github.workspace }}
+jobs:
+  build-and-release:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+            arch: X64
+          - goos: linux
+            goarch: arm64
+            arch: ARM64
+          - goos: linux
+            goarch: arm
+            goarch_variant: "6"
+            arch: ARM
+          - goos: linux
+            goarch: "386"
+            arch: X86
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 1.24
+      - name: Generate version from commit SHA
+        id: version
+        run: ./scripts/distribute.sh generate-version
+      - name: Create distribute directory
+        run: ./scripts/distribute.sh create-distribute-directory "${{ matrix.arch }}"
+      - name: Clone apt-fast repository
+        run: ./scripts/distribute.sh clone-apt-fast
+      - name: Build binary for ${{ matrix.goos }}/${{ matrix.goarch }}
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+          GOARM: ${{ matrix.goarch_variant }}
+          CGO_ENABLED: 0
+        run: |
+          ./scripts/distribute.sh build-binary \
+            "${{ matrix.goos }}" \
+            "${{ matrix.goarch }}" \
+            "${{ matrix.goarch_variant }}" \
+            "${{ matrix.arch }}"
+      - name: Generate checksums
+        run: ./scripts/distribute.sh generate-checksums "${{ matrix.arch }}"
+      - name: Verify build
+        run: |
+          ./scripts/distribute.sh verify-build "${{ matrix.arch }}"
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: cache-apt-pkgs-${{ matrix.arch }}-${{ steps.version.outputs.commit_sha }}
+          path: distribute/${{ matrix.arch }}/*
+          retention-days: 30
+  create-release:
+    needs: build-and-release
+    runs-on: ubuntu-latest
+    if: success()
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Generate version from commit SHA
+        id: version
+        run: |
+          COMMIT_SHA="${GITHUB_SHA:0:8}"
+          VERSION="${{ env.VERSION_PREFIX }}-${COMMIT_SHA}"
+          echo "version=${VERSION}" >> $GITHUB_OUTPUT
+          echo "commit_sha=${COMMIT_SHA}" >> $GITHUB_OUTPUT
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: distribute-artifacts
+      - name: Reorganize artifacts
+        run: |
+          ./scripts/distribute.sh reorganize-artifacts
+      - name: Create or update release
+        uses: softprops/action-gh-release@v1
+        with:
+          tag_name: ${{ steps.version.outputs.version }}
+          name: "${{ steps.version.outputs.version }}"
+          generate_release_notes: true
+          files: |
+            distribute/x64/*
+            distribute/arm64/*
+            distribute/arm/*
+            distribute/x86/*
+          draft: false
+          prerelease: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Clean up old pre-releases
+        run: |
+          echo "Cleaning up old commit-based releases..."
+          # Keep last 10 commit-based releases, delete older ones
+          gh release list --limit 50 --json tagName,isPrerelease | \
+            jq -r '.[] | select(.isPrerelease == true and (.tagName | startswith("commit-"))) | .tagName' | \
+            tail -n +11 | \
+            xargs -I {} gh release delete {} --yes --cleanup-tag || true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/shellcheck.yml

@@ -0,0 +1,28 @@
+name: ShellCheck
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+  push:
+    branches:
+      - master
+      - dev
+      - staging
+
+permissions:
+  contents: read
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Run ShellCheck
+        uses: ludeeus/action-shellcheck@master
+        with:
+          scandir: '.'
+          format: gcc
+          severity: style
+

.gitignore

@@ -1,2 +1,3 @@
 src/cmd/apt_query/apt_query*
-*.log
+apt_query*
+*.log

.shellcheckrc

@@ -0,0 +1,31 @@
+# ShellCheck configuration file
+# See https://github.com/koalaman/shellcheck/wiki/Directives for more information
+
+# Enable all optional checks
+enable=all
+
+# Disable specific warnings that may be acceptable in this project
+# SC1090: Can't follow non-constant source. Use a path to a file that can be checked
+#         (disabled because we use dynamic sourcing with script_dir)
+disable=SC1090
+
+# SC1091: Not following: <file> was not specified as input
+#         (disabled because lib.sh is sourced dynamically)
+disable=SC1091
+
+# SC2310: Function invoked in && condition (set -e disabled)
+#         (acceptable pattern for conditional execution)
+disable=SC2310
+
+# SC2311: Bash implicitly disabled set -e in command substitution
+#         (acceptable pattern - we want to capture output even if function fails)
+disable=SC2311
+
+# SC2312: Consider invoking command separately to avoid masking return value
+#         (many of these are acceptable patterns in command substitutions)
+disable=SC2312
+
+# Exclude external files that we don't control
+exclude-dir=.git
+exclude-dir=testlogs
+

README.md

@@ -154,3 +154,84 @@ For more context and information see [issue #57](https://github.com/awalsh128/ca
 ### Cache Limits
 
 A repository can have up to 5GB of caches. Once the 5GB limit is reached, older caches will be evicted based on when the cache was last accessed. Caches that are not accessed within the last week will also be evicted. To get more information on how to access and manage your actions's caches, see [GitHub Actions / Using workflows / Cache dependencies](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#viewing-cache-entries).
+
+## Development
+
+### Prerequisites
+
+- **Go 1.20+** (for building the `apt_query` binary) - version specified in `go.mod`
+  - Install from [golang.org](https://golang.org/dl/) or via package manager
+  - Verify installation: `go version`
+- **ShellCheck** (for linting shell scripts) - install via:
+  - macOS: `brew install shellcheck`
+  - Linux: `sudo apt-get install shellcheck` or see [shellcheck installation guide](https://github.com/koalaman/shellcheck#installing)
+  - Windows: Available via [scoop](https://scoop.sh/) or [chocolatey](https://chocolatey.org/)
+
+### Building
+
+The project includes Go binaries (`apt_query-arm64` and `apt_query-x86`) that are used by the shell scripts to query APT package information.
+
+**Build all packages:**
+```bash
+go build -v ./...
+```
+
+**Build for specific architecture:**
+```bash
+# For ARM64 (Apple Silicon, ARM servers)
+GOARCH=arm64 go build -o apt_query-arm64 ./src/cmd/apt_query
+
+# For x86_64 (Intel/AMD)
+GOARCH=amd64 go build -o apt_query-x86 ./src/cmd/apt_query
+```
+
+**Run tests:**
+```bash
+go test -v ./...
+```
+
+### Linting
+
+This project uses [ShellCheck](https://github.com/koalaman/shellcheck) to ensure shell script quality and catch common errors. The configuration is stored in `.shellcheckrc`.
+
+**Run ShellCheck locally:**
+```bash
+shellcheck *.sh
+```
+
+**IDE Integration:**
+
+Many IDEs and editors can automatically run ShellCheck:
+
+- **VS Code**: Install the [ShellCheck extension](https://marketplace.visualstudio.com/items?itemName=timonwong.shellcheck)
+- **Vim/Neovim**: Use [ALE](https://github.com/dense-analysis/ale) or [coc-shellcheck](https://github.com/josa42/coc-shellcheck)
+- **IntelliJ/CLion**: ShellCheck is integrated in recent versions
+- **Sublime Text**: Install [SublimeLinter-shellcheck](https://github.com/SublimeLinter/SublimeLinter-shellcheck)
+
+**Go Linting:**
+
+This project uses [golangci-lint](https://golangci-lint.run/) for Go code quality checks.
+
+**Run golangci-lint locally:**
+```bash
+# Install golangci-lint (if not already installed)
+# macOS: brew install golangci-lint
+# Linux: See https://golangci-lint.run/usage/install/
+
+golangci-lint run
+```
+
+**IDE Integration:**
+
+- **VS Code**: Install the [Go extension](https://marketplace.visualstudio.com/items?itemName=golang.go) for syntax highlighting, auto-completion, and built-in linting
+- **IntelliJ/GoLand**: Built-in Go support with linting and formatting
+- **Vim/Neovim**: Use [vim-go](https://github.com/fatih/vim-go) for Go development
+
+### CI/CD
+
+The GitHub Actions workflows will automatically:
+- **Build and test** Go code on pull requests
+- **Run ShellCheck** on shell scripts (blocks PRs on failures)
+- **Run golangci-lint** on Go code (blocks PRs on failures)
+
+All checks run on pull requests and pushes to `master`, `dev`, and `staging` branches.

action.yml

@@ -81,7 +81,7 @@ runs:
 
     - id: load-cache
       if: ${{ env.CACHE_KEY }}
-      uses: actions/cache/restore@v5
+      uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
       with:
         path: ~/cache-apt-pkgs
         key: cache-apt-pkgs_${{ env.CACHE_KEY }}
@@ -110,14 +110,14 @@ runs:
 
     - id: upload-logs
       if: ${{ env.CACHE_KEY && inputs.debug == 'true' }}
-      uses: actions/upload-artifact@v7
+      uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
       with:
         name: cache-apt-pkgs-logs_${{ env.CACHE_KEY }}
         path: ~/cache-apt-pkgs/*.log
 
     - id: save-cache
       if: ${{ env.CACHE_KEY && ! steps.load-cache.outputs.cache-hit }}
-      uses: actions/cache/save@v5
+      uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
       with:
         path: ~/cache-apt-pkgs
         key: ${{ steps.load-cache.outputs.cache-primary-key }}

install_and_cache_pkgs.sh

@@ -19,7 +19,7 @@ cache_dir="${1}"
 add_repository="${3}"
 
 # List of the packages to use.
-input_packages="${@:4}"
+input_packages="${*:4}"
 
 if ! apt-fast --version > /dev/null 2>&1; then
   log "Installing apt-fast for optimized installs..."
@@ -31,7 +31,7 @@ if ! apt-fast --version > /dev/null 2>&1; then
 fi
 
 # Add custom repositories if specified
-if [ -n "${add_repository}" ]; then
+if [[ -n "${add_repository}" ]]; then
   log "Adding custom repositories..."
   for repository in ${add_repository}; do
     log "- Adding repository: ${repository}"
@@ -42,12 +42,7 @@ if [ -n "${add_repository}" ]; then
 fi
 
 log "Updating APT package list..."
-if [[ -z "$(find -H /var/lib/apt/lists -maxdepth 0 -mmin -5)" ]]; then
+update_apt_lists_if_stale
-  sudo apt-fast update > /dev/null
-  log "done"
-else
-  log "skipped (fresh within at least 5 minutes)"
-fi
 
 log_empty_line
 
@@ -76,7 +71,10 @@ install_log_filepath="${cache_dir}/install.log"
 
 log "Clean installing ${package_count} packages..."
 # Zero interaction while installing or upgrading the system via apt.
-sudo DEBIAN_FRONTEND=noninteractive apt-fast --yes install ${packages} > "${install_log_filepath}"
+# Note: sudo doesn't affect redirects, but we want the output in the file anyway
+# shellcheck disable=SC2024
+# We intentionally redirect output here; the redirect happens as the current user which is fine
+sudo DEBIAN_FRONTEND=noninteractive apt-fast --yes install "${packages}" > "${install_log_filepath}"
 log "done"
 log "Installation log written to ${install_log_filepath}"
 
@@ -86,7 +84,7 @@ installed_packages=$(get_installed_packages "${install_log_filepath}")
 log "Installed package list:"
 for installed_package in ${installed_packages}; do
   # Reformat for human friendly reading.  
-  log "- $(echo ${installed_package} | awk -F\= '{print $1" ("$2")"}')"
+  log "- $(echo "${installed_package}" | awk -F= '{print $1" ("$2")"}')"
 done
 
 log_empty_line
@@ -98,20 +96,20 @@ for installed_package in ${installed_packages}; do
 
   # Sanity test in case APT enumerates duplicates.
   if test ! -f "${cache_filepath}"; then
-    read package_name package_ver < <(get_package_name_ver "${installed_package}")
+    read -r package_name package_ver < <(get_package_name_ver "${installed_package}")
     log "  * Caching ${package_name} to ${cache_filepath}..."
 
     # Pipe all package files (no folders), including symlinks, their targets, and installation control data to Tar.
     tar -cf "${cache_filepath}" -C / --verbatim-files-from --files-from <(
       { dpkg -L "${package_name}" &&
-        get_install_script_filepath "" "${package_name}" "preinst" &&
+        { get_install_script_filepath "/" "${package_name}" "preinst" ;
-        get_install_script_filepath "" "${package_name}" "postinst" ; } |
+        get_install_script_filepath "/" "${package_name}" "postinst" ; } ; } |
       while IFS= read -r f; do
         if test -f "${f}" -o -L "${f}"; then
           get_tar_relpath "${f}"
-          if [ -L "${f}" ]; then
+          if [[ -L "${f}" ]]; then
             target="$(readlink -f "${f}")"
-            if [ -f "${target}" ]; then
+            if [[ -f "${target}" ]]; then
               get_tar_relpath "${target}"
             fi
           fi
@@ -125,7 +123,7 @@ for installed_package in ${installed_packages}; do
   # Comma delimited name:ver pairs in the all packages manifest.
   manifest_all="${manifest_all}${package_name}=${package_ver},"
 done
-log "done (total cache size $(du -h ${cache_dir} | tail -1 | awk '{print $1}'))"
+log "done (total cache size $(du -h "${cache_dir}" | tail -1 | awk '{print $1}'))"
 
 log_empty_line
 

lib.sh

@@ -17,14 +17,16 @@ set +e
 #   Filepath of the install script, otherwise an empty string.
 ###############################################################################
 function execute_install_script {
-  local package_name=$(basename ${2} | awk -F\= '{print $1}')  
+  local package_name
-  local install_script_filepath=$(\
+  package_name=$(basename "${2}" | awk -F= '{print $1}')  
+  local install_script_filepath
+  install_script_filepath=$(\
     get_install_script_filepath "${1}" "${package_name}" "${3}")
   if test ! -z "${install_script_filepath}"; then
     log "- Executing ${install_script_filepath}..."
     # Don't abort on errors; dpkg-trigger will error normally since it is
     # outside its run environment.
-    sudo sh -x ${install_script_filepath} ${4} || true
+    sudo sh -x "${install_script_filepath}" "${4}" || true
     log "  done"
   fi
 }
@@ -40,9 +42,17 @@ function execute_install_script {
 ###############################################################################
 function get_install_script_filepath {
   # Filename includes arch (e.g. amd64).
-  local filepath="$(\
+  local filepath
-    ls -1 ${1}var/lib/dpkg/info/${2}*.${3} 2> /dev/null \
+  # Use glob expansion instead of ls|grep for better handling of non-alphanumeric filenames
-    | grep -E ${2}'(:.*)?.'${3} | head -1 || true)"
+  # Use nullglob to prevent literal match when no files found
+  shopt -s nullglob
+  for f in "${1}"var/lib/dpkg/info/"${2}"*."${3}"; do
+    if [[ -f "${f}" ]] && [[ "${f}" =~ ${2}'(:.*)?.'"${3}" ]]; then
+      filepath="${f}"
+      break
+    fi
+  done
+  shopt -u nullglob
   test "${filepath}" && echo "${filepath}"
 }
 
@@ -66,7 +76,7 @@ function get_installed_packages {
       log_err "Unable to parse package name and version from \"${line}\""
       exit 2
     fi
-  done < <(grep "^Unpacking " ${install_log_filepath})
+  done < <(grep "^Unpacking " "${install_log_filepath}")
   if test -n "${dep_packages}"; then
     echo "${dep_packages:0:-1}"  # Removing trailing space.
   else
@@ -83,13 +93,13 @@ function get_installed_packages {
 ###############################################################################
 function get_package_name_ver {
   local ORIG_IFS="${IFS}"
-  IFS=\= read name ver <<< "${1}"
+  IFS='=' read -r name ver <<< "${1}"
   IFS="${ORIG_IFS}"
   # If version not found in the fully qualified package value.
   if test -z "${ver}"; then
     # This is a fallback and should not be used any more as its slow.
     log_err "Unexpected version resolution for package '${name}'"
-    ver="$(apt-cache show ${name} | grep '^Version:' | awk '{print $2}')"
+    ver="$(apt-cache show "${name}" | grep '^Version:' | awk '{print $2}')"
   fi
   echo "${name}" "${ver}"  
 }
@@ -105,16 +115,19 @@ function get_normalized_package_list {
   # Remove commas, and block scalar folded backslashes,
   # extraneous spaces at the middle, beginning and end
   # then sort.
-  local packages=$(echo "${1}" \
+  local packages
+  packages=$(echo "${1}" \
     | sed 's/[,\]/ /g; s/\s\+/ /g; s/^\s\+//g; s/\s\+$//g' \
     | sort -t' ')
-  local script_dir="$(dirname -- "$(realpath -- "${0}")")"
+  local script_dir
+  script_dir="$(dirname -- "$(realpath -- "${0}")")"
 
-  local architecture=$(dpkg --print-architecture)
+  local architecture
-  if [ "${architecture}" == "arm64" ]; then
+  architecture=$(dpkg --print-architecture)
-    ${script_dir}/apt_query-arm64 normalized-list ${packages}
+  if [[ "${architecture}" == "arm64" ]]; then
+    "${script_dir}"/apt_query-arm64 normalized-list "${packages}"
   else
-    ${script_dir}/apt_query-x86 normalized-list ${packages}
+    "${script_dir}"/apt_query-x86 normalized-list "${packages}"
   fi
 }
 
@@ -127,14 +140,42 @@ function get_normalized_package_list {
 #   The relative filepath to archive.
 ###############################################################################
 function get_tar_relpath {
-  local filepath=${1}
+  local filepath="${1}"
-  if test ${filepath:0:1} = "/"; then
+  if test "${filepath:0:1}" = "/"; then
     echo "${filepath:1}"
   else
     echo "${filepath}"
   fi
 }
 
+###############################################################################
+# Updates APT package lists if they are stale (modified more than 5 minutes ago).
+# This ensures compatibility with environments like nektos/act where package lists
+# may be empty or stale. Only runs when ACT environment variable is set (nektos/act)
+# to avoid slowing down normal GitHub Actions runs.
+# Arguments:
+#   None
+# Returns:
+#   None
+###############################################################################
+function update_apt_lists_if_stale {
+  # Only check for stale package lists when running in nektos/act
+  # GitHub Actions runners have fresh package lists, so skip this overhead
+  if [ "${ACT}" = "true" ]; then
+    if [[ -z "$(find -H /var/lib/apt/lists -maxdepth 0 -mmin -5 2>/dev/null)" ]]; then
+      log "APT package lists are stale, updating..."
+      if command -v apt-fast > /dev/null 2>&1; then
+        sudo apt-fast update > /dev/null 2>&1 || sudo apt update > /dev/null 2>&1 || true
+      else
+        sudo apt update > /dev/null 2>&1 || true
+      fi
+      log "APT package lists updated"
+    else
+      log "APT package lists are fresh (within 5 minutes), skipping update"
+    fi
+  fi
+}
+
 function log { echo "${@}"; }
 function log_err { >&2 echo "${@}"; }
 
@@ -153,7 +194,7 @@ function validate_bool {
   if test "${1}" != "true" -a "${1}" != "false"; then
     log "aborted"
     log "${2} value '${1}' must be either true or false (case sensitive)."
-    exit ${3}
+    exit "${3}"
   fi
 }
 
@@ -167,12 +208,12 @@ function validate_bool {
 #   Log lines from write.
 ###############################################################################
 function write_manifest {  
-  if [ ${#2} -eq 0 ]; then 
+  if [[ ${#2} -eq 0 ]]; then 
     log "Skipped ${1} manifest write. No packages to install."
   else
     log "Writing ${1} packages manifest to ${3}..."
     # 0:-1 to remove trailing comma, delimit by newline and sort.
-    echo "${2:0:-1}" | tr ',' '\n' | sort > ${3}
+    echo "${2:0:-1}" | tr ',' '\n' | sort > "${3}"
     log "done"
   fi
 }

post_cache_action.sh

@@ -29,12 +29,12 @@ test "${debug}" = "true" && set -x
 add_repository="${6}"
 
 # List of the packages to use.
-packages="${@:7}"
+packages="${*:7}"
 
 if test "${cache_hit}" = "true"; then
-  ${script_dir}/restore_pkgs.sh "${cache_dir}" "${cache_restore_root}" "${execute_install_scripts}" "${debug}"
+  "${script_dir}"/restore_pkgs.sh "${cache_dir}" "${cache_restore_root}" "${execute_install_scripts}" "${debug}"
 else
-  ${script_dir}/install_and_cache_pkgs.sh "${cache_dir}" "${debug}" "${add_repository}" ${packages}
+  "${script_dir}"/install_and_cache_pkgs.sh "${cache_dir}" "${debug}" "${add_repository}" "${packages}"
 fi
 
 log_empty_line

pre_cache_action.sh

@@ -10,7 +10,7 @@ source "${script_dir}/lib.sh"
 # Setup first before other operations.
 debug="${4}"
 validate_bool "${debug}" debug 1
-test ${debug} == "true" && set -x
+test "${debug}" == "true" && set -x
 
 # Directory that holds the cached packages.
 cache_dir="${1}"
@@ -28,15 +28,20 @@ debug="${4}"
 add_repository="${5}"
 
 # List of the packages to use.
-input_packages="${@:6}"
+# Use * instead of @ to concatenate array elements into a single string
+input_packages="${*:6}"
 
 # Trim commas, excess spaces, and sort.
 log "Normalizing package list..."
+
+# Ensure APT package lists are updated if stale (for nektos/act compatibility)
+update_apt_lists_if_stale
+
 packages="$(get_normalized_package_list "${input_packages}")"
 log "done"
 
 # Create cache directory so artifacts can be saved.
-mkdir -p ${cache_dir}
+mkdir -p "${cache_dir}"
 
 log "Validating action arguments (version='${version}', packages='${packages}')...";
 if grep -q " " <<< "${version}"; then
@@ -47,7 +52,9 @@ fi
 
 # Is length of string zero?
 if test -z "${packages}"; then
-  case "$EMPTY_PACKAGES_BEHAVIOR" in
+  # shellcheck disable=SC2154
+  # EMPTY_PACKAGES_BEHAVIOR is an environment variable passed from GitHub Actions
+  case "${EMPTY_PACKAGES_BEHAVIOR}" in
     ignore)
       exit 0
       ;;
@@ -66,7 +73,7 @@ fi
 validate_bool "${execute_install_scripts}" execute_install_scripts 4
 
 # Basic validation for repository parameter
-if [ -n "${add_repository}" ]; then
+if [[ -n "${add_repository}" ]]; then
   log "Validating repository parameter..."
   for repository in ${add_repository}; do
     # Check if repository format looks valid (basic check)
@@ -100,13 +107,13 @@ log "- CPU architecture is '${cpu_arch}'."
 value="${packages} @ ${version} ${force_update_inc}"
 
 # Include repositories in cache key to ensure different repos get different caches
-if [ -n "${add_repository}" ]; then
+if [[ -n "${add_repository}" ]]; then
   value="${value} ${add_repository}"
   log "- Repositories '${add_repository}' added to value."
 fi
 
 # Don't invalidate existing caches for the standard Ubuntu runners
-if [ "${cpu_arch}" != "x86_64" ]; then
+if [[ "${cpu_arch}" != "x86_64" ]]; then
   value="${value} ${cpu_arch}"
   log "- Architecture '${cpu_arch}' added to value."
 fi
@@ -119,5 +126,5 @@ log "- Value hashed as '${key}'."
 log "done"
 
 key_filepath="${cache_dir}/cache_key.md5"
-echo ${key} > ${key_filepath}
+echo "${key}" > "${key_filepath}"
 log "Hash value written to ${key_filepath}"

restore_pkgs.sh

@@ -6,7 +6,7 @@ set -e
 # Debug mode for diagnosing issues.
 # Setup first before other operations.
 debug="${4}"
-test ${debug} == "true" && set -x
+test "${debug}" == "true" && set -x
 
 # Include library.
 script_dir="$(dirname -- "$(realpath -- "${0}")")"
@@ -18,30 +18,33 @@ cache_dir="${1}"
 # Root directory to untar the cached packages to.
 # Typically filesystem root '/' but can be changed for testing.
 cache_restore_root="${2}"
-test -d ${cache_restore_root} || mkdir ${cache_restore_root}
+test -d "${cache_restore_root}" || mkdir "${cache_restore_root}"
 
 # Cache and execute post install scripts on restore.
 execute_install_scripts="${3}"
 
-cache_filepaths="$(ls -1 "${cache_dir}" | sort)"
+# Use find instead of ls to better handle non-alphanumeric filenames
-log "Found $(echo ${cache_filepaths} | wc -w) files in the cache."
+cache_filepaths="$(find "${cache_dir}" -mindepth 1 -maxdepth 1 -type f -o -type d | sort)"
+file_count=$(echo "${cache_filepaths}" | wc -w)
+log "Found ${file_count} files in the cache."
 for cache_filepath in ${cache_filepaths}; do
-  log "- "$(basename ${cache_filepath})""
+  log "- $(basename "${cache_filepath}")"
 done
 
 log_empty_line
 
 log "Reading from main requested packages manifest..."
-for logline in $(cat "${cache_dir}/manifest_main.log" | tr ',' '\n' ); do
+while IFS= read -r logline; do
   log "- $(echo "${logline}" | tr ':' ' ')"
-done
+done < <(tr ',' '\n' < "${cache_dir}/manifest_main.log")
 log "done"
 
 log_empty_line
 
 # Only search for archived results. Manifest and cache key also live here.
-cached_filepaths=$(ls -1 "${cache_dir}"/*.tar 2>/dev/null | sort)
+# Use find instead of ls to better handle non-alphanumeric filenames
-cached_filecount=$(echo ${cached_filepaths} | wc -w)
+cached_filepaths=$(find "${cache_dir}" -maxdepth 1 -name "*.tar" -type f 2>/dev/null | sort)
+cached_filecount=$(echo "${cached_filepaths}" | wc -w)
 
 log "Restoring ${cached_filecount} packages from cache..."
 for cached_filepath in ${cached_filepaths}; do
@@ -51,7 +54,7 @@ for cached_filepath in ${cached_filepaths}; do
   log "  done"
 
   # Execute install scripts if available.    
-  if test ${execute_install_scripts} == "true"; then
+  if test "${execute_install_scripts}" == "true"; then
     # May have to add more handling for extracting pre-install script before extracting all files.
     # Keeping it simple for now.
     execute_install_script "${cache_restore_root}" "${cached_filepath}" preinst install

src/cmd/apt_query/testlogs/testnormalizedlist_virtualpackagesexists_stdoutsconcretepackage.log

@@ -10,10 +10,10 @@
 EXECUTION-OBJ-END
 2025/03/15 22:29:14 EXECUTION-OBJ-START
 {
- "Cmd": "bash -c apt-cache showpkg libvips | grep -A 1 \"Reverse Provides\" | tail -1",
+ "Cmd": "apt-cache showpkg libvips",
- "Stdout": "libvips42 8.9.1-2 (= )\n",
+ "Stdout": "Package: libvips\nReverse Provides:\nlibvips42 8.9.1-2 (= )\n",
  "Stderr": "",
- "CombinedOut": "libvips42 8.9.1-2 (= )\n",
+ "CombinedOut": "Package: libvips\nReverse Provides:\nlibvips42 8.9.1-2 (= )\n",
  "ExitCode": 0
 }
 EXECUTION-OBJ-END

src/internal/common/apt.go

@@ -33,20 +33,36 @@ func isErrLine(line string) bool {
 
 // Resolves virtual packages names to their concrete one.
 func getNonVirtualPackage(executor exec.Executor, name string) (pkg *AptPackage, err error) {
-	execution := executor.Exec("bash", "-c", fmt.Sprintf("apt-cache showpkg %s | grep -A 1 \"Reverse Provides\" | tail -1", name))
+	execution := executor.Exec("apt-cache", "showpkg", name)
 	err = execution.Error()
 	if err != nil {
 		logging.Fatal(err)
 		return pkg, err
 	}
-	if isErrLine(execution.CombinedOut) {
+
-		return pkg, execution.Error()
+	inReverseProvides := false
+	for _, line := range strings.Split(execution.CombinedOut, "\n") {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "" {
+			continue
+		}
+		if trimmed == "Reverse Provides:" {
+			inReverseProvides = true
+			continue
+		}
+		if !inReverseProvides || strings.HasPrefix(trimmed, "W: ") || isErrLine(trimmed) {
+			continue
+		}
+		if strings.HasSuffix(trimmed, ":") {
+			break
+		}
+		splitLine := GetSplitLine(trimmed, " ", 3)
+		if len(splitLine.Words) < 2 {
+			continue
+		}
+		return &AptPackage{Name: splitLine.Words[0], Version: splitLine.Words[1]}, nil
 	}
-	splitLine := GetSplitLine(execution.CombinedOut, " ", 3)
+	return pkg, fmt.Errorf("unable to parse reverse provides package name and version from apt-cache showpkg output below:\n%s", execution.CombinedOut)
-	if len(splitLine.Words) < 2 {
-		return pkg, fmt.Errorf("unable to parse space delimited line's package name and version from apt-cache showpkg output below:\n%s", execution.CombinedOut)
-	}
-	return &AptPackage{Name: splitLine.Words[0], Version: splitLine.Words[1]}, nil
 }
 
 func getPackage(executor exec.Executor, paragraph string) (pkg *AptPackage, err error) {

src/internal/common/apt_test.go

@@ -0,0 +1,53 @@
+package common
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	execpkg "awalsh128.com/cache-apt-pkgs-action/src/internal/exec"
+)
+
+type mockExecutor struct {
+	executions map[string]*execpkg.Execution
+}
+
+func (s mockExecutor) Exec(name string, arg ...string) *execpkg.Execution {
+	cmd := name + " " + strings.Join(arg, " ")
+	execution, ok := s.executions[cmd]
+	if !ok {
+		panic(fmt.Sprintf("unexpected command: %s", cmd))
+	}
+	return execution
+}
+
+func TestGetNonVirtualPackage_WithWarningsInReverseProvides(t *testing.T) {
+	executor := mockExecutor{
+		executions: map[string]*execpkg.Execution{
+			"apt-cache showpkg libopenblas0-openmp": {
+				Cmd: "apt-cache showpkg libopenblas0-openmp",
+				CombinedOut: strings.Join([]string{
+					"Package: libopenblas0-openmp",
+					"Reverse Provides:",
+					"libopenblas0-openmp 0.3.26+ds-1ubuntu0.1 (= )",
+					"W: Unable to read /etc/apt/apt.conf.d/99github-actions - open (13: Permission denied)",
+					"",
+				}, "\n"),
+				ExitCode: 0,
+			},
+		},
+	}
+
+	pkg, err := getNonVirtualPackage(executor, "libopenblas0-openmp")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if pkg == nil {
+		t.Fatal("expected package but got nil")
+	}
+
+	expected := AptPackage{Name: "libopenblas0-openmp", Version: "0.3.26+ds-1ubuntu0.1"}
+	if *pkg != expected {
+		t.Fatalf("unexpected package.\nexpected: %+v\nactual: %+v", expected, *pkg)
+	}
+}