title: Create React App produces different chunk file names for same code from different CI jobs
body: <p>We have a CI setup which builds a React app via Dockerfile into an Nginx image.</p>
  <p>Now we want to upload source maps for the same commit to Sentry but in a separate job.</p>
  <p>I have read <a href="https://github.com/facebook/create-react-app/issues/5526#issuecomment-431861378" rel="nofollow noreferrer">this comment on Github</a> already and made sure that the <code>WORKDIR</code> in the Dockerfile is exactly the same absolute path as the job's directory for the Sentry source map upload job.</p>
  <p>However, both React builds produce different file names:</p>
  <pre><code>403.55 KB  build/static/js/2.0bd71bf6.chunk.js
  165.73 KB  build/static/js/main.f6fff2fd.chunk.js
  37.5 KB    build/static/css/main.031b7dea.chunk.css
  784 B      build/static/js/runtime-main.96388d36.js
  </code></pre>
  <p>vs.</p>
  <pre><code>403.59 KB  build/static/js/2.1bf300db.chunk.js
  165.78 KB  build/static/js/main.acdd9b95.chunk.js
  37.5 KB    build/static/css/main.031b7dea.chunk.css
  784 B      build/static/js/runtime-main.96388d36.js
  </code></pre>
  <p>I tried to read into the responsible Webpack plugins but it's been quite a difficult journey so far to fully understand what is the exact input for a <code>contenthash</code>. I hope anyone has an idea?</p>