CI: Warn longstanding development revision of bundled gems

.github/workflows/bundled_gems.yml

@@ -100,6 +100,48 @@ jobs:
           gems: ${{ steps.diff.outputs.gems }}
         if: ${{ steps.diff.outputs.update }}
 
+      - name: Fetch more logs
+        id: logs
+        run: |
+          file=gems/bundled_gems days=30
+          { echo days=$days; echo file=$file; } >> $GITHUB_OUTPUT
+          since=$(date --date=-$[days * 2 + 10]day +'%F')
+          set -x
+          git sparse-checkout set --no-cone /$file
+          git fetch --shallow-since="$since" --no-tags origin ${GITHUB_REF}
+
+      - name: Development revision of bundled gems
+        run: |
+          #!ruby
+          file = ENV["file"]
+          days = ENV["days"].to_i
+          today = Time.new("#{ENV['TODAY']}T00:00:00Z").to_i
+          limit = today - days * 86400
+
+          ok = true
+          IO.popen(%W"git blame --line-porcelain -- #{file}") do |blame|
+            while head = blame.gets("\n\t") and s = blame.gets
+              next unless (gem = s.split(/\s+|#.*/)).size > 3
+              time = head[/^committer-time \K\d+/].to_i
+              next if (d = limit - time) <= 0
+              d /= 86400
+              line = head[/\A\h+ \d+ \K\d+/].to_i
+              level = if d < days; 'warning'; else ok = false; 'error'; end
+              d += days
+              puts "::#{level} file=#{file},line=#{line},title=Older than #{d} days::#{gem[0]} #{gem[3]}"
+            end
+          end
+          # exit ok
+        shell: ruby {0}
+        env:
+          file: ${{ steps.logs.outputs.file }}
+          days: ${{ steps.logs.outputs.days }}
+
+      - name: Restore sparse checkout
+        run: |
+          git sparse-checkout disable
+        if: always()
+
       - name: Install libraries
         uses: ./.github/actions/setup/ubuntu
         if: ${{ steps.diff.outputs.gems }}