Fix CI script

Signed-off-by: Paolo Di Tommaso <paolo.ditommaso@gmail.com>

Author: pditommaso

.github/workflows/build.yml

@@ -39,17 +39,18 @@ jobs:
         run: |
             if [ "${{ github.event_name }}" = "pull_request" ]; then
                 echo "GitHub event=pull_request"
-                COMMIT_SHA=${{ github.event.pull_request.head.sha }}
-                COMMIT_MESSAGE=$(curl -s \
+                COMMIT_SHA="${{ github.event.pull_request.head.sha }}"
+                COMMIT_MESSAGE="$(curl -s \
                   -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-                  https://api.github.com/repos/${{ github.repository }}/commits/$COMMIT_SHA | jq -r '.commit.message')
+                  https://api.github.com/repos/${{ github.repository }}/commits/$COMMIT_SHA | jq -r '.commit.message')"
                 echo "Commit message=$COMMIT_MESSAGE" | head -n 1
                 echo "commit_message=$COMMIT_MESSAGE" | head -n 1 >> $GITHUB_OUTPUT
             else
-               echo "GitHub event=${{ github.event_name }}"
-               echo "Commit message=${{ github.event.head_commit.message }}" | head -n 1
-               echo "commit_message=${{ github.event.head_commit.message }}" | head -n 1 >> $GITHUB_OUTPUT
-            fi 
+                echo "GitHub event=${{ github.event_name }}"
+                COMMIT_MESSAGE="${{ github.event.head_commit.message }}"
+                echo "Commit message=$COMMIT_MESSAGE" | head -n 1
+                echo "commit_message=$COMMIT_MESSAGE" | head -n 1 >> $GITHUB_OUTPUT
+            fi
 
       - name: Get changed files
         id: changed-files