This is my GitHub Actions script to build a react project:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
        with:
          node-version: 14
      - name: Install yarn
        uses: borales/actions-yarn@v2.1.0
      - name: Build React App
        run: | 
          sudo rm -rf node_modules
          yarn
          umi build

when I run this project in GitHub actions, shows error:

warning "umi-serve > @babel/preset-typescript@7.3.3" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "umi-serve > @babel/register@7.4.4" has unmet peer dependency "@babel/core@^7.0.0-0".
warning Workspaces can only be enabled in private projects.
warning Workspaces can only be enabled in private projects.
[5/5] Building fresh packages...
error An unexpected error occurred: "EACCES: permission denied, open '/home/runner/work/admin/admin/yarn.lock'".
info If you think this is a bug, please open a bug report with the information provided in "/home/runner/work/admin/admin/yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
Error: Process completed with exit code 1.

why could not access the project yarn.lock when using yarn command? why facing the permission issue in GitHub Actions? what should I do to fix this problem?

>Solution :

I also facing the similar issue with it, you should tried to use actions/setup-node like this to fix it:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-node@v2
        with:
          node-version: 16
      - run: npm install yarn -g
      - name: Build React App
        run: | 
          yarn
          yarn global add umi
          umi build