title: How do I upgrade an existing Flutter app?
body: <p>I have an existing Flutter app that I built half a year ago. I checked on pubspec.lock, it has this line:</p>
  <pre><code>sdks:
    dart: &quot;&gt;=2.10.0-110 &lt;2.11.0&quot;
    flutter: &quot;&gt;=1.16.0 &lt;2.0.0&quot;
  </code></pre>
  <p>So I assume the app was built for Flutter v1.16.</p>
  <ol>
  <li><p>How do I upgrade this app to use the latest Flutter's version? Running &quot;flutter doctor&quot; gives me <code>[√] Flutter (Channel stable, 1.22.3, on Microsoft Windows [Version 10.0.19041.630], locale en-US)</code>, so my SDK is already updated to the latest version.</p>
  </li>
  <li><p>Interestingly, when I create a new app from scratch, the pubspec.lock does not have any information about the Flutter's version. The same section now contains only this: <code>sdks: dart: &quot;&gt;=2.10.0-110 &lt;2.11.0&quot;</code>. In the future, how would I know which version was this app running?</p>
  </li>
  </ol>
  <p>I have tried running &quot;flutter upgrade&quot; within my app, but that was to upgrade the SDK, not the Flutter version of the app. So how do I upgrade my app to use the latest Flutter version? Or is it always built using the latest version of the SDK? Can't I target my app to build with specific version of Flutter?</p>