ci: fix std-action bug with empty build matrix

Author: michalrus

.github/workflows/std.yml

@@ -67,25 +67,29 @@ jobs:
     name: ${{ matrix.target.jobName }}
     runs-on: ubuntu-latest
     needs: discover
-    if: fromJSON(needs.discover.outputs.hits).oci-images.publish != '{}'
     strategy:
       matrix:
-        target: ${{ fromJSON(needs.discover.outputs.hits).oci-images.publish }}
+        target: ${{ contains(fromJSON(needs.discover.outputs.hits), 'oci-images') && fromJSON(needs.discover.outputs.hits).oci-images.publish || fromJSON('["dummy-target"]') }}
     steps:
       - name: Configure AWS Credentials
+        if: matrix.target != 'dummy-target'
         uses: aws-actions/[email protected]
         with:
           role-to-assume: ${{ env.AWS_ROLE_ARN }}
           aws-region: ${{ env.AWS_REGION }}
       - name: Login to Amazon ECR
+        if: matrix.target != 'dummy-target'
         id: login-ecr
         uses: aws-actions/amazon-ecr-login@v1
       - uses: nixbuild/nix-quick-install-action@v25
+        if: matrix.target != 'dummy-target'
       - uses: nixbuild/nixbuild-action@v17
+        if: matrix.target != 'dummy-target'
         with:
           nixbuild_ssh_key: ${{ secrets.SSH_PRIVATE_KEY }}
           generate_summary_for: job
       - uses: divnix/std-action/setup-discovery-ssh@main
+        if: matrix.target != 'dummy-target'
         with:
           ssh_key: ${{ secrets.SSH_PRIVATE_KEY }}
           user_name: ${{ env.DISCOVERY_USER_NAME }}
@@ -95,6 +99,7 @@ jobs:
         run: |
           echo commit: ${{ github.sha }}
       - uses: divnix/std-action/run@main
+        if: matrix.target != 'dummy-target'
         with: {ffBuildInstructions: true, remoteStore: "ssh-ng://eu.nixbuild.net"}