Problem

The GitHub Actions workflow file .github/workflows/main.yml had an invalid YAML structure that caused the error:

Invalid workflow file
(Line: 1, Col: 14): A sequence was not expected

The file only contained a step definition fragment without the required workflow structure:

             - name: Deploy GitHub Pages site
  uses: actions/[email protected]
  with:
    # GitHub token
    token: # default is ${{ github.token }}
    ...

This is invalid because:

• The step started with incorrect indentation at the root level
• Missing required top-level keys (name, on, jobs)
• No workflow triggers defined
• No job wrapper around the deployment step

Solution

Created a complete, properly structured GitHub Actions workflow that deploys static content to GitHub Pages:

name: Deploy static content to Pages

on:
  push:
    branches: ["main"]
  workflow_dispatch:

permissions:
  contents: read
  pages: write
  id-token: write

concurrency:
  group: "pages"
  cancel-in-progress: false

jobs:
  deploy:
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
      - name: Setup Pages
        uses: actions/configure-pages@v4
      - name: Upload artifact
        uses: actions/upload-pages-artifact@v3
        with:
          path: '.'
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v4

Key Changes

• ✅ Added workflow name declaration
• ✅ Added on triggers (push to main + manual workflow_dispatch)
• ✅ Configured required permissions for Pages deployment
• ✅ Added concurrency control to prevent deployment conflicts
• ✅ Wrapped deployment step in proper jobs structure with environment configuration
• ✅ Added complete deployment workflow: checkout → setup → upload → deploy
• ✅ Used latest action versions (@v4 for checkout, configure-pages, deploy-pages)

The workflow now follows GitHub's official pattern for static site deployment and will successfully deploy the portfolio site to GitHub Pages.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.