title: Flutter: Setting constraints for package versions in pubspec.yaml
body: <p>I used <a href="https://pub.dev/packages/share" rel="nofollow noreferrer">share</a> package, share pacakge document said add like this, </p>
  
  <pre><code> share: "&gt;=0.6.y+x &lt;2.0.0"
  </code></pre>
  
  <p><strong>Please set your constraint to share: '>=0.6.y+x &lt;2.0.0'</strong></p>
  
  <p>after run pub get, I got this error,</p>
  
  <pre><code>Error on line 65, column 10 of pubspec.yaml: Invalid version constraint: Expected version number after "&gt;=" in "&gt;=0.6.y+x &lt;2.0.0", got "0.6.y+x &lt;2.0.0".
  
     ╷
  
  65 │   share: "&gt;=0.6.y+x &lt;2.0.0"
  
     │          ^^^^^^^^^^^^^^^^^^
  
     ╵
  pub get failed (65;    ╵)
  </code></pre>