Sanitize the registry image name

.github/workflows/docker-publish.yaml

@@ -5,29 +5,37 @@ on:
   push:
 
 env:
-  REGISTRY_IMAGE: ghcr.io/${{ github.repository }}
   # Only push images on forks or the main branch
   PUSH_IMAGE: ${{ (github.ref_name == 'master') || (github.repository_owner != 'moos-ivp') }}
 
 jobs:
   prepare:
     runs-on: ubuntu-latest
     outputs:
-      commit_time: ${{ steps.prepare.outputs.commit_time }}
+      commit_time: ${{ steps.prepare.outputs.COMMIT_TIMESTAMP }}
+      registry_image: ${{ steps.prepare.outputs.REGISTRY_IMAGE }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
-      - name: Prepare commit timestamp
+      - name: Prepare various metadata
         id: prepare
         run: |
+          # Get the commit timestamp
           export "COMMIT_TIMESTAMP=$(git log -1 --pretty=%ct)"
-          echo "COMMIT_TIMESTAMP = $COMMIT_TIMESTAMP"
-          echo $COMMIT_TIMESTAMP >> $GITHUB_OUTPUT
+          echo "COMMIT_TIMESTAMP=$COMMIT_TIMESTAMP" | tee $GITHUB_OUTPUT
+
+          # Lowercase the repository name
+          UNSANITIZED_REGISTRY_IMAGE=ghcr.io/${{ github.repository }}
+          echo "REGISTRY_IMAGE=${UNSANITIZED_REGISTRY_IMAGE,,}" | tee $GITHUB_OUTPUT
+          
 
   build-minrobot:
     runs-on: ubuntu-latest
+    needs:
+      - prepare
     env:
       SOURCE_DATE_EPOCH: ${{ needs.prepare.outputs.commit_time }}
+      REGISTRY_IMAGE: ${{ needs.prepare.outputs.registry_image }}
     outputs:
       # So we can `FROM` this image in the next build
       digest: ${{ steps.build.outputs.digest }}
@@ -76,11 +84,13 @@ jobs:
 
   build-gui:
     runs-on: ubuntu-latest
-    needs: 
+    needs:
+      - prepare
       - build-minrobot
     env:
       FLAVOR: "-gui"
       SOURCE_DATE_EPOCH: ${{ needs.prepare.outputs.commit_time }}
+      REGISTRY_IMAGE: ${{ needs.prepare.outputs.registry_image }}
     steps:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3