Stop early if no relevant changes

Author: thinkall

.github/workflows/python-package.yml

@@ -24,7 +24,6 @@ concurrency:
 
 jobs:
   build:
-
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -33,6 +32,28 @@ jobs:
         python-version: ["3.9", "3.10", "3.11"]
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Required to get full history for diff
+      - name: Check for relevant file changes
+        id: changes
+        run: |
+          echo "Changed files:"
+          git fetch origin main
+          CHANGED_FILES=$(git diff --name-only origin/main...HEAD)
+          echo "$CHANGED_FILES"
+
+          MATCH=$(echo "$CHANGED_FILES" | grep -E '^flaml/|^test/|^notebook/|^setup.py|^\.github/workflows/python-package.yml' || true)
+
+          if [ -z "$MATCH" ]; then
+            echo "No relevant changes detected. Skipping build."
+            echo "skip=true" >> $GITHUB_OUTPUT
+          else
+            echo "Relevant changes detected. Proceeding with build."
+            echo "skip=false" >> $GITHUB_OUTPUT
+          fi
+      - name: Stop early if no relevant changes
+        if: steps.changes.outputs.skip == 'true'
+        run: echo "Skipping rest of the build job." && exit 0
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with: