refactor: enhance error handling in build_package function and add repository access testing in CI workflow

Author: BarkinKctp

.github/workflows/build-citus-community-nightlies.yml

@@ -42,6 +42,23 @@ jobs:
           app-id: ${{ vars.GH_APP_ID }}
           private-key: ${{ secrets.GH_APP_KEY }}
           owner: ${{ github.repository_owner }}
+          repositories: citus,packaging,tools
+
+      - name: Debug - Test token access to repos
+        env:
+          GH_TOKEN: ${{ steps.app.outputs.token }}
+        run: |
+          echo "Testing token access to repositories..."
+          for repo in citus packaging tools; do
+            echo "Testing access to citusdata/$repo..."
+            if gh api repos/citusdata/$repo --jq '.full_name' 2>/dev/null; then
+              echo "✓ Access to citusdata/$repo OK"
+            else
+              echo "✗ No access to citusdata/$repo"
+            fi
+          done
+          echo "Token scopes:"
+          curl -sS -H "Authorization: Bearer $GH_TOKEN" https://api.github.com/rate_limit | head -20
 
       - name: Checkout repository
         uses: actions/checkout@v3

packaging_automation/citus_package.py

@@ -360,7 +360,10 @@ def build_package(
     if output.stdout:
         print("Output:" + output.stdout)
     if output.returncode != 0:
-        raise ValueError(output.stderr)
+        error_msg = f"Docker command failed with return code {output.returncode}\n"
+        error_msg += f"STDOUT:\n{output.stdout}\n" if output.stdout else "STDOUT: (empty)\n"
+        error_msg += f"STDERR:\n{output.stderr}\n" if output.stderr else "STDERR: (empty)\n"
+        raise ValueError(error_msg)
 
     if input_output_parameters.output_validation:
         validate_output(